achieving operational excellence in power generation

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Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 53 Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools A Quality Initiative Success Story at NTPC Ltd. Western Region-II ABSTRACT In the changing scenario of the power sector and ever increasing stringent environmental and regulatory norms, NTPC power plants need to operate efficiently and with high reliability. On real time basis when a unit is in operation there are number of process parameters which needs focused attention to achieve the higher level of efficiency and reliability. This project is an outcome of an innovative thought on achieving zero aberration in the process parameters. In order to achieve the target of zero aberration, project deployed DMAIC approach and used quality tools like Failure Mode Effect Analysis (FMEA), Fish Bone, Pareto, IMR Charts, Poka- Yoke etc. and embedding the same with Information Technology (IT) tools, Plant Information (PI) module for real time monitoring & solutions. The key project deliverables are improvement in processes and arresting process deviations to improve efficiency and reliability of units.

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Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 53

Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools

A Quality Initiative Success Story at NTPC Ltd. Western Region-II

ABSTRACTIn the changing scenario of the power sector and ever increasing stringent environmental and regulatory norms, NTPC power plants need to operate efficiently and with high reliability. On real time basis when a unit is in operation there are number of process parameters which needs focused attention to achieve the higher level of efficiency and reliability. This project is an outcome of an innovative thought on achieving zero aberration in the process parameters. In order to achieve the target of zero aberration, project deployed DMAIC approach and used quality tools like Failure Mode Effect Analysis (FMEA), Fish Bone, Pareto, IMR Charts, Poka-Yoke etc. and embedding the same with Information Technology (IT) tools, Plant Information (PI) module for real time monitoring & solutions.

The key project deliverables are improvement in processes and arresting process deviations to improve efficiency and reliability of units.

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Table Showing Basic Causes of Aberrations

Basic Cause Reason Criterion Liability Responsibility

Mother Nature Design Problem

Design parameters 1. not achieved in PG test.

Never achieved the 2. design parameter and PG test not completed yet.

Engineering Issues

CC- Engineering

Machine, Material

Equipment Health

Equipment not 1. performing as per PG test value

OH/SD Job MTP Head

Machine, Measurement

Control Malfunction

Card/Metering 1. Equipment malfunction

Logical Problem2.

BD Job MTP Head

Method Operation Induced

Incorrect /delayed 1. action by control Engineers

System was 2. demanding but no action taken by Control Engineers

Incorrect Line –up of 3. system

Inadvertent selection4.

Training/ Discussions

Operation Head/EDC Head

Method Maintenance Induced:

Poor workmanship 1. by Maintenance people

Non availability of 2. spares

Material defect3.

Training/ Procurement/ Analysis

HOD (Maintenance)/C&M//NETRA

Measurement Aberration Limits/Display Issue

Limits are stringent 1. than design (Please Give Limits with reference)

Limits to be modified 2. (Please Give Limits with reference)

Wrong PI tag 3. Selection (Please give Correct PI Tag)

IT related AGM (OS)/ DGM (IT) at WR-II

Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 55

Prologue

February 25, 2011 marked the beginning of a new Regional Head Quarters of NTPC Ltd. at Raipur looking into the potential growth of business in Chhattisgarh & Madhya Pradesh. By April, 2011 a small team at the newly formed Regional HQ was entrusted the responsibility to support the Operations of the three Super Thermal Power Station of this new Region WR-II comprising of Korba (2600 MW), Sipat (2980 MW) & Vindhyachal (3760 MW).

An innovative idea sparked for capturing the plant process parameters, make them readily available in user friendly visual format to the team at Raipur for analysing and ultimately with objective of process improvement - Target-To Achieve ‘ZERO’ Aberration of Critical Process Parameters.

The idea to reality with whole hearted efforts within a couple of months has proved today to be one of the ever best initiatives for operational excellence embedding Quality & IT tools.

Actualisation of Idea

There are more than 2000 process parameters for each unit available in the Plant Information (PI) Server; the initial challenge was to identifying the critical process parameters which are CTQ and to make them available at the desk top of the team members.

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Series of Brain Storming sessions along with Operation Engineers from the Station was held in this context, focus was on capturing & analysing the parameters which had direct impact on the bottom line as well as those which delighted our customers.

Accordingly at the end of 5 to 6 Brain Storming sessions, the team zeroed down with around 40 parameters which had high impact on Reliability and Efficiency of the Units.

Reliability Parameters: The Parameters where deviations result in Forced Outage, Breakdown of Equipments, thereby Loss of Generation, for example, Super Heater and Re-Heater Metal Temperatures, Flue Gas Temperatures, Chemical Parameters etc.

Efficiency Parameters: The parameters where deviations result in higher inputs like Coal Feed Rate, Make Up Water, Air, Auxiliary Power Consumption etc. Deviations in these parameters also affect the environment, for example, Steam temperatures, Steam Pressures, Exit Flue Gas Temperatures, and Oxygen Percent.

Figure Showing Web Display of Critical Parameters

Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 57

Figure Showing Web Display of Chemistry Parameters

Figure Showing Web Display of 24 Hours Aberration Report of Critical Parameters

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Figure Showing Web Display of 24 Hours Aberration Report of Chemistry Parameters

Figure Showing Web Display of Pain Area Identification

Figure Showing Web Display of Aberration Trend from August, 12 to March, 13, Station: Sipat

Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 59

Figure Showing Web Display of Trend of Critical Parameter with UCL and LCL

Figure Showing Web Display of Example of Trend Display of Critical Parameter with UCL and LCL

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Figure Showing Web Display of Example of Trend Display of Critical Parameter with UCL and LCL

On completing the crucial task of identifying the CTQ process parameters the next step was to identifying the PI Tags for each of the 40 critical parameters. There was a continuous interaction with Station C & I Engineers for accomplishing the same. Parallel to this the task of Web-Page Design, Configuring the Identified PI Tags and Coding Work was also in full swing by the WR-II HQ IT team.

For each identified critical parameters, Upper Control Limit (UCL) and Lower Control Limit (LCL) was earmarked based on the OEM recommendations, design values and also that on the present operating value of the parameters. Further, control chart for each parameter was freezed with Poka-Yoke option and additional features like viewing of historical data on a click helped in analysing the deviation and going to root cause.

Apart from the Unit Boiler, Turbine, Generator Process Parameters, the team also worked on identifying around 8 Water & Steam Chemistry Parameters which are critical for reliable operation of the plant. Similar approach and exercise as that of the Unit 40 Parameters was adopted for the selected Chemistry Parameters with display on a separate web page. These chemical parameters have huge financial implication resulting in reduction of Boiler Tube Leakage, Improvement in Turbine Efficiency etc.

Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 61

Plotting of Real Time Rolling Curves to Control the Gap between Desired and Actual

Excited with positive outcomes of the above exercise, the team further worked on capturing the Loading & Rolling parameters in its journey of operational excellence. Unit start-ups are periods when plant equipments are subjected to very adverse thermal conditions. Turbine is the key equipment for any power plant. Any failure in this equipment leads to shut down of power plant. So a safe operation of this type of equipment is a must. When turbine is rolled from a barring speed to 3000 RPM, there are certain thermal conditions laid down in Turbine operation manual. To monitor the real time rolling against the designed conditions, “Rolling and Loading Curves” have been developed. One can see this rolling curve at his desktop computer from the remote location; he doesn’t need to go to Unit Control Room. The archived rolling and loading curves can also be used for training purpose for the new-comers.

Whenever deviations in design rolling parameters occur (please see Figure 10 given below), the reflection comes in unit loading (please see Figure 11 given below) and this ultimately, results either in Loss of generation due to slow loading or undesired stress on turbo generator due to fast loading.

Figure Showing Web Display of Example of Rolling Curve

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Figure Showing Web Display of Example of Unit Loading Curve (Actual vs. Design Loading)

WR-II OS team interacts with Station O & M personnel to analyse the deviations occurred in Rolling and Loading as and when it is required.

Display of Turbovisory Parameters

Further, in the process to bring out critical parameters from boundary of Unit Control Room, a web application has been developed to display the Vibration, Temperature and other vital parameters of Most Critical Equipment of a power plant, i.e. Turbo Generator. It is pictorial display of turbine as seen in control room by operation engineers, please see figure 12 given below:

Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 63

Figure Showing Web Display of Turbovisory Parameters

Change Management

Taking the innovative idea from the drawing board to its actualisation and simultaneous implementation at all the three Stations of Western Region-II was the next challenge. However, the involvement of young O&M engineers from Stations along with the team at WR-II HQ, right from the stage of inception of the idea made the things easier. Further, it was made acceptable to all Heads of O&M and was deliberated in length at the 2nd Regional Management Committee meeting held at Raipur in which all the Station Heads were present. The initiative got a smooth sailing thereafter with defined responsibility centres for different activities and also for inclusion of Root Cause Analysis of parameters aberrations.

The system developed includes creation of 24 hrs Aberration Report and booking of aberration liability, the same has been detailed in the following Flow-Chart:

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Figure Showing FLOW-CHART of Aberration Liability Application

Each responsibility centre has owned the change and has widely accepted the initiative as an important element for gaining competitive advantage.

Moreover, within a year of implementation there have been measurable financial and tangible benefits.

Critical Parameter identification

Display of Critical Parameter

Generation of Report for Aberration(Occurred in last 24 Hours)

Root cause analysis at station level aswell as Regional HQ for aberration

Pain Area Identification(Fortnightly Basis)

(Report of Aberration occurred more than10 Days in a fortnight)

Root cause filling by Station O&M Team

Vetting of data(filled at Station)by Regional OS

Committeeof Station

O&M Headand ROSHead

If not agreed

Aberration goes to Liabilitybasket for planning the jobs

to be carried out

If agreed

Achieving Operational Excellence in Power Generation Through Integration of Quality and IT Tools 65

Business Improvement

1. Direct saving of Rs. 117.84 Cr during the year 2012-13.

2. Availability of the process parameters in the desk top of each key personnel of O&M.

3. Developing an on-line system for capturing the liability of the unit.

4. Better appreciation of the processes.

5. In-depth Root Cause Analysis.

6. Sustainable and to be emulated across all the operating Stations of NTPC.

Financial Benefits

By end of 2011-12 the project was implemented in WR-II Stations, hence the improvement in process parameters resulting in reduction of Forced Outage, Partial loss & Heat Rate in 2012-13 as compared to 2011-12 is considered for the financial gain:

2011-12

2012-13

Savings in Units Savings/Extra Earning in Crores (Approx.)

Installed Capacity (MW)

62992 75007

Forced Outage (Equipment)

% of Installed Capacity

4.64% 3.46% = 75007x106*(4.64-3.46)*0.01= 885 x 106 UnitsSaleable Units= (Generated Units – APC)=885 x106 x 0.930= 803.05 x 106 Units

Average Fixed Charges1 Rs/KWHTotal Recovery in Fixed Charges=80.305 CroresFor Variable Charges= Saleable Units x Marginal Contribution= 803.05 x 106 x 0.03= 24.09 CroresTotal: 80.3 + 24.09 = 104.39 Cr

Partial Loss (Equipment)

% of Installed Capacity

0.58% 0.42% = 75007x106*(0.58-0.42)*0.01= 90 x 106 UnitsSaleable Units= (Generated Units – APC)=90 x106 x 0.930= 83.7 x 106 Units

Average Fixed Charges1 Rs/KWHTotal Recovery in Fixed Charges=8.37 CroresFor Variable Charges= Saleable Units x Marginal Contribution= 83.7 x 106 x 0.03= 2.51 CroresTotal: 8.37 + 2.51 = 10.88 Cr

Heat Rate Kcal/KWH

2368 2367 Energy Saving=75007 x 106* (2368-2367)= 75007 x 106 KcalAssuming GCV of Coal as 3500 KCal/KgThen Saving in terms of Coal will be= 75007 x 106/3500= 21430571 Kg of Coal

Cost of 1 Kg coal Approx. 1.2 Rs/KgTotal saving=2.57 Crore

Net Financial Gain = Rs 117.84 Crores

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