Efficiency Improvement by Loss Minimization

2010 APEX MEA AwardsEfficiency improvement by loss minimization

AES OPGC India

AES Corporation 2/

Team

Team Name :- Efficiency improvement Team

Team Sponsor :- Venkatachalam Kupusami

Team Members :-

Amalendu Nanda

Manoj Ku. Jit

Madhumita Soren

Manoj Ku. Pradhan

Deepak Ranjan Tripathy

Tarini Patnaik

Amrit Bal

Facilitator

Sukanta Mohapatra

AES Corporation 3/

Team Charter (problem or issue )

Background

OPGC –I station which is now 16 years old requires system modifications, which is being carried out

in the form of DCS up gradation, excitation system control up gradation and coal feeder up gradation

etc. for sustainability and reduction of forced outages on account of control system related issues.

OPGC team on a sustainable basis has taken steps on energy management front. We wanted to

focus on the areas where we can benefit from performance or efficiency improvement with minimum

investment.

Team decided to list out the energy losses and rectify the same with an objective to enhance the

station performance.

Basically, we thought of improving efficiency through loss Reduction wherever possible by process

optimisation, adherence to standard checklist, carrying out small modifications, controlled use of

equipment wherever possible for cost optimisation and better resource utilisation.

AES Corporation 4/

Team Charter (Risks of not doing this project)

Steam Loss of 18142 T /Y

Bloated Budgeted Station oil consumption by 88 KL per year.

Increased Auxiliary power consumption 148982 kWhr

Deteriorating Station performance

Higher Maintenance Cost

Underutilized Resources

Unscrupulous expenditure

Low Maintenance effectiveness ratio

Low Availability / Reliability of equipments

AES Corporation 5/

Team Charter ( Goal & Objective )

Goal Objective

Take out one out of two service Air Ejector from Unit-1 Increasing the steam turbine output.

Check & Rectify Steam Traps in :

Boiler Area.

Turbine Area.

Maximum utilization of heat.

Maintain less Oil Pressure while taking Oil Guns Reduce Oil Consumption

BFP recirculation valve passing Auxiliary power consumption

Modification of Circuit to run One HFO Pump Lesser Auxiliary Power Consumption

AES Corporation 6/

Findings (Approach – method, Tools )

The Team used the PDCA approach, with the following APEX Tools utilized:

Brainstorming

Check sheets

Data Gathering by samples

FIRE

GAP Analysis

Gantt Chart

Implementation Plan 5W2H

AES Corporation 7/

Conducting Brainstorming Sessions

– Identify and brief a leader or facilitator ( Amalendu Nanda was identified as Leader)

– Introduce the brainstorming session

The Leader welcomed participants and described the purpose of the session, roles and

responsibilities, and the facilities.

The Leader used a structured approach and allowed every person in the group to give their

ideas as their turns came up in the rotation or to pass until the next round.

Identified Focus Areas

Performance or efficiency improvement with minimum investment.

Energy losses listing & rectification.

Future Impetus

Improving efficiency through loss reduction by

Process optimisation

Adherence to standard checklist

Carrying out small modifications

Controlled use of equipment

Position/Role Name Knowledge Area/Expertise

Team Lead Amalendu Nanda Operation & efficiency

Knowledge Mgr. Manoj Ku. Jit Operation

Knowledge Mgr. Madhumita Soren Performance & efficiency

Knowledge Mgr. Manoj Ku. Pradhan Mechanical Maintenance

Knowledge Mgr. Deepak Ranjan Tripathy Head WTP

Brainstorming

AES Corporation 8/

Alternatives discussed

Take out one service Air Ejector from Unit-1

Check & Rectify Steam Traps in :Boiler Area & Turbine Area.

Maintain less Oil Pressure while taking Oil Guns

BFP recirculation valve passing

Modification of Circuit to run One HFO Pump

Condenser and Cooling Tower Performance Improvement

Optimization of soot blowing process

Unit 1- Performance evaluation to be done by reducing excess air to boiler

Mill ball feeding based on requirement

Boiler Flue gas duct & APH duct leakage to be reduced.

Heater Performance enhancement

Identified Projects (For this Year)

Take out one service Air Ejector from Unit-1

Check & Rectify Steam Traps in :Boiler Area & Turbine Area

Maintain less Oil Pressure while taking Oil Guns

BFP recirculation valve passing

Modification of Circuit to run One HFO Pump

Rest Projects will be taken up in subsequent years. Identified projects scored over the rest on

grounds of low investment higher returns.

Brainstorming

AES Corporation 9/

Organizational Scope

Operation and Maintenance teams are involved in the project.

Team Activity Scope

Sl No. Project Activities

01 Discussion on the project regarding its feasibility with different concerned

parties, Proposed modification.

02 Study of all the points one by one through field survey

03 Work on every points simultaneously for completion of project in time

04 Carry out modification as per requirement

05 Required spare to be ordered for modification

06 Project completion and trial implementation

Brainstorming

AES Corporation 10/

Gap Analysis

Current State Two Main air ejectors are used for air extraction and creating vacuum in the condenser in Unit-1.

Steam required for one Main Ejectors is 1TPH.

60% of steam traps are passing causing steam loss.

Maintaining 6.5ksc of oil pressure while taking Oil Guns.

Oil flow of 1.4KL per gun.

Pneumatic recirculation valve of BFP -2B is passing 30T.

Drawing extra current of 10Amp.

Two HFO pumps are kept in service during normal conditions even when oil guns are not in service.

Gap• Identification & rectification of air

ingress points.

• Improve the capacity of the Main air ejector .

• Checking of Steam Trap.

• Replacement of defective Steam Traps

• Maintaining lower oil pressure for reduced oil flow per gun.

• Servicing / Replacing of the Recirculation Valve that is passing.

• Necessary modification to be done for interconnecting both Unit-1 & 2 HFO Stations

Future State• Running with one Air Ejector in

Unit-1 .

• Utilize 1TPH steam for increasing the steam turbine output.

• All the Steam traps in service for retaining steam within the process for maximum utilization of heat.

• Maintain the Oil Pressure at 6 ksc while taking Oil Guns.

• Oil flow of 1.3KL per gun.

• Passing proof recirculation valve will reduce the current run by the BFP.

• Reduction in Auxiliary power consumption by 101.737KWH

• One HFO pump in service.

AES Corporation 11/

5W2H ( Air Ejector )

Type 5W2H Question

Subject Matter What?

What will be done?

Take out one service Air Ejector from Unit-1.

Identification & rectification of air ingress points.

Purpose Why?Why will it be done?

Increase the steam turbine output.

Location Where?Where will it be done?

Turbine Area Unit-1

Sequence When?

When does it need to be done?

Are there time constraints, deadlines?

People Who?Who will do it?

M.K.Pradhan, A.P.Nanda, M.K.Jit

Method How?

How will it be done?

How will the tasks be approached and managed?

1. Carryout required trouble shooting operation and carryout modification in the system to

improve the capacity of the Main air ejector so that vacuum can be sustained with single

service air ejector.

2. Take out one service Air Ejector from Unit-1.

Cost How Much?

How much will it cost?

How much investment is required?

No significant investment as the job would be performed by in-house expertise and

material requirement is also not significant.

How much return is expected?

Revenue from extra generation = 2299500*0.41= 9,42,795 INR

Start Date End Date

25/09/2010 30/12/2010

5W2H

AES Corporation 12/

5W2H ( Steam Traps )

Type 5W2H Question

Subject Matter What?What will be done?

Checking/Replacement of defective Steam Traps

Purpose Why?

Why will it be done?

60% of steam traps are passing causing steam loss.

Steam loss due to defective traps = 0.1*21*365*24*0.85*0.6 = 9381.96 T/ Yr


Turbine Side, Deaerator Floor, PRDS Floor , Mill Area

Sequence When?




M.K.Jit , Madhumita Soren

Method How?



Checking of Steam Trap has been done by

•Visual inspection,

•Checking by Ultra probe,

•Temperature checking

Replacement of 12 defective Steam Traps

Cost How Much?



Cost of 12 traps = 12X5000 = 60,000INR


Revenue from extra generation = 2814600*0.41=11,53,986 INR

Start Date End Date

02/11/2010 30/12/2010

5W2H

AES Corporation 13/

5W2H (Optimising Oil Pressure )

Type 5W2H Question


Reducing oil consumption by optimizing oil Pressure while unit is on oil support

Purpose Why?

Why will it be done?

Reducing oil pressure reduces oil flow through the oil guns, thus reducing the oil

consumption.


Oil fired boilers use oil guns for start-up, warm-up, and load carrying.

Sequence When?




Sudhakar Swain, Madhumita Soren

Method How?



Maintain the Oil Pressure at 6 ksc instead of 6.5ksc while taking Oil Guns. This will

reduces the oil flow by 0.1 KL per gun from 1.4KL per gun to 1.3 KL per Gun.

Cost How Much?



NIL


Benefit of Rs 37,00,000 is expected

Start Date End Date

01/09/2010 30/12/2010

5W2H

AES Corporation 14/

5W2H (BFP recirculation valve passing )

Type 5W2H Question


Prevent BFP recirculation valve passing


Reduction of auxiliary consumption


BFP 2B (Unit 2 boiler feed pump)

Sequence When?




A.P.Nanda, Amrit Bal

Method How?


30T of passing through recirculation valve of BFP-2B.

BFP 2B (Unit 2 boiler feed pump) is drawing extra current of 10Amp.

Passing is prevented, then there is a auxiliary saving potential .

Cost How Much?



Recirculation valve spare 3,00,000INR


Savings potentials per year = 101.73X24X365X0.85X (2/3) X1.3 = 6, 56,484 INR

Start Date End Date

02/11/2010 30/12/2010

5W2H

AES Corporation 15/

5W2H (Using One HFO Pump )

Type 5W2H Question


Running of single HFO pump instead of two during normal operating condition of both

Units.


Lesser Auxiliary Power Consumption


Unit-1 & 2 HFO Stations

Sequence When?




Sudhakar Swain, A.P.Nanda

Method How?



1.Stopping of One HFO Pump.

2. Necessary modification to be done for interconnecting both Unit-1 & 2 HFO Stations

Cost How Much?



Material cost: INR 10,000


Annual Savings (in Rs) = Rs 1, 95,033

Start Date End Date

Completed ( 30/07/2010)

( Under Trial Observation)

5W2H

AES Corporation 16/

Findings (Issues and Root Causes)1. Unit-1: One of the Main air ejectors to be taken out of service

Two Main air ejectors are in service in Unit-1 due to inadequacy in the performance of single Main air

ejector. Though several attempts have been made to keep one Main air ejector in service, we have

not been able to succeed, so far.

Team would like to carryout required trouble shooting operation and carryout modification in the

system to improve the capacity of the Main air ejector so that vacuum can be sustained with single

service air ejector. APEX tool will be used in performing this task.

Steam required for one Main Ejectors is 1TPH. If we can take out one ejector then we would be able

to utilize 1TPH steam for increasing the steam turbine output.

2. Steam Trap:

The function of a steam trap is to discharge condensate, air and other incondensable gases from a

steam system while not permitting the escape of live steam. The steam trap is an essential part of any

steam system. It is the important link between good steam and condensate management, retaining

steam within the process for maximum utilization of heat, but releasing condensate and

incondensable gases at the appropriate time.

At OPGC, Thermostatic Type of Steam Traps are used and are operated by changes in fluid

temperature. In total 21 nos. of trap (10 nos in Unit 1 & 11nos in Unit 2) are in service.

Defective stream traps have been identified by taking temperature measurement across each trap. It

is observed that 60% of steam traps are passing causing steam loss.

AES Corporation 17/

Findings (Issues and Root Causes)

3. Oil Gun flow optimisation :

In coal fired boilers the oil guns are used for start-up and warm-up purpose. Oil fired boilers use them

for start-up, warm-up, and load carrying. These oil guns are designed with a capacity of around thirty

percent of boiler maximum continuous rating. Oil guns are used during initial start up of unit for light-

up of the boiler, for taking coal mill into service when adjacent mills are not in operation and as a

flame stabilization fuel.

In present practice, we are maintaining 6.5ksc of oil pressure while taking Oil Guns. This caters to oil

flow of 1.4KL per gun.

We are planning to maintain the Oil Pressure at 6 ksc while taking Oil Guns. This will reduces the oil

flow by 0.1 KL per gun.

4. BFP Recirculation:

It has been seen that there is nearly 30T of passing through recirculation valve of BFP-2B. As a result

BFP 2B (Unit 2 boiler feed pump) is drawing extra current of 10Amp. If passing is prevented, then

there is a saving potential .

5. Using One HFO Pump

Currently, two HFO pumps are kept in service. There is a plan to keep one HFO pump in service after

doing suitable modification in the circuit.

AES Corporation 18/

Solution Implementation (Addressing Issues )

Running with one Air Ejector in Unit-1 (Currently two ejectors are in service in Unit-1) :

Identification & rectification of air ingress points.

Checking/Replacement of defective Steam Traps in :

Boiler Area.

Turbine Area.

Reduce Oil Consumption by Optimising Oil Pressure.

Reducing oil pressure reduces oil flow through the oil guns, thus reducing the oil consumption.

Reducing Auxiliary Power consumption

Rectify recirculation valve passing of BFP and CEP.

Checking of individual pumps for Recirculation valve passing and taking steps to rectify

Stopping of One HFO Pump

Necessary modification to be done for interconnecting both Unit-1 & 2 HFO Stations

AES Corporation 19/

Solution Implementation (Solution superseded any

other solutions)Other ways of Improving Efficiency were as follows

Condenser and Cooling Tower Performance Improvement

Optimization of soot blowing process

Unit 1- Performance evaluation to be done by reducing excess air to boiler

Mill ball feeding based on requirement

Boiler Flue gas duct & APH duct leakage to be reduced.

Heater Performance enhancement

But these efficiency improvement measures superseded all other possible measures in terms of

Financial returns and appreciable impact on KPIs

Increasing the steam turbine output.- Steam required for one Main Ejectors is 1TPH. If we can take

out one ejector then we would be able to utilize 1TPH steam for increasing the steam turbine output.

Maximum utilization of heat- Defective stream traps have been identified by taking temperature

measurement across each trap. It is observed that 60% of steam traps are passing causing steam

loss.

Reduce Oil Consumption - In present practice, we are maintaining 6.5ksc of oil pressure while taking

Oil Guns. This caters to oil flow of 1.4KL per gun. We are planning to maintain the Oil Pressure at 6

ksc while taking Oil Guns. This will reduces the oil flow by 0.1 KL per gun.

Auxiliary power consumption - It has been seen that there is nearly 30T of passing through

recirculation valve of BFP-2B. As a result BFP 2B (Unit 2 boiler feed pump) is drawing extra current of

10Amp. If passing is prevented, then there is a saving potential.

Lesser Power Consumption - Modification of process/ control Circuit to run One HFO Pump

AES Corporation 20/

Solution Implementation (Implementation plan)Activity/Milestone Start Date End Date

Collect information of the feasibility of the project. 25/06/2010 30/06/2010

Finalization of the project plan and submission for approval 02/07/2010 15/07/2010

Discussion strategy for carrying out all the jobs simultaneously 20/07/2010 25/07/2010

Necessary Modifications 27/07/2010 30/12/2010

Offer to be asked from different parties for the required spares.

( Procurement of steam traps, Recirculation valve spare )

02/10/2010 24/11/2010

Completion of the project & report finalization after 15 days trial 05/12/2010 20/12/2010

Necessary Modifications Start Date End Date

Take out one service Air Ejector from Unit-1 25/09/2010 30/12/2010

Check & Rectify Steam Traps in :

Boiler Area.

Turbine Area.

02/11/2010 30/12/2010

Maintain less Oil Pressure while taking Oil Guns 01/09/2010 30/12/2010

BFP recirculation valve passing 02/11/2010 30/12/2010

Modification of Circuit to run One HFO Pump Completed ( 30/07/2010)

( Under Trial Observation)

AES Corporation 21/

Results: Business impact in Performance

The Following Issues were addressed -

Steam Loss of 18142 T /Y

Bloated Budgeted Station oil consumption by 88 KL per year.

Increased Auxiliary power consumption 148982 kWhr

Forced outages ( Trips )

Deteriorating Station performance

Higher Maintenance Cost

Underutilized Resources

Unscrupulous expenditure

Maintenance effectiveness ratio

Availability ,Reliability of equipments

AES Corporation 22/

Results: Business financial benefitsAir Ejector

Cost savings:

For 210 MW Generation steam flow requirement is 680T

So, 1 T of steam flow will generate 0.3MW.

So, Generation improvement per year by running 1 ejector = (210/680*365*24*0.85) =

2299.5MW=2299500 KWhr

Revenue from extra generation = 2299500*0.41= 9,42,795 INR = $ 20951.

Investment:

No significant investment as the job would be performed by in-house expertise and material

requirement is also not significant.

Steam Traps

Cost savings:

Steam loss due to defective traps = 0.1*21*365*24*0.85*0.6 = 9381.96 T/ Yr

For 210 MW Generation steam flow requirement is 680T

So, 1 T of steam flow will generate 0.3MW.

So, Generation improvement per year by replacing defective traps =

(210/680*9382) = 2814.6MW=2814600KWhr.

Revenue from extra generation = 2814600*0.41=11,53,986 INR = $ 25644

Investment:

No significant investment as the job would be performed by in-house expertise

Material replacement

12 number of traps to be replaced

Cost of 12 traps = 12X5000 = 60,000INR = ($1333 )

AES Corporation 23/

Results: Business financial benefits

Oil Gun flow optimisation :

Cost Benefit

Budgeted Station oil consumption is 1230KL per year.

If we reduced the flow from 1.4KL per gun to 1.3 KL per gun, then the consumption would be reduced

to 1142 KL per year.

Thus a benefit of Rs 37,00,000 ($ 82222 ) is expected.

Investment:

No significant investment as the job would be performed by in-house expertise

Material cost: Nil

BFP Recirculation:

Cost Benefit:

If passing is prevented, then there is a saving potential of

Auxiliary power consumption = 1.732 x 6.6 x 10 x 0.89 = 101.737KWH

Savings per year = 101.73X24X365X0.85X (2/3) X1.3 = 6, 56,484 INR ($ 14589 )

Note: BFP recirculation valve passing checks to be carried out for Unit-1

Investment:

Manpower cost: In-house manpower

Material cost: Recirculation valve spare 3,00,000INR ($6667)

AES Corporation 24/


Using One HFO Pump

Cost Benefit:

Power of Drive Motor for HFO is 22KW (for calculation we will consider 20KW)

Total working hours = Total hours of Operation – Average hours when both the Pumps are needed

= (331 * 24) – (500)

= 7444 hrs

Annual Savings (in Rs) = (20 x 7444) x 1.31

= Rs 1, 95,033 ($ 4334 )

Investment:

Manpower cost: In-house manpower

Material cost: INR 10,000 ($ 222 )

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Investment

Cost of 12 traps $ 1333

Material cost: Recirculation valve spare $ 6667

Material cost for Modification in Circuit for running 1 HFO Pump $ 222

Total Cost:- $8222

Cost Savings

Air Ejector :- $ 20951

Steam Traps :- $ 25644

Oil Guns :- $ 82222

BFP Recirculation:- $ 14589

HFO Pump :- $ 4334

Total Annual Benefits:- $ 147740

Pay Back Period :- less than a 1 Month

NPV :- $ 20704209

AES Corporation 26/

Knowledge Learned as a team

OPGC team believed that If a team is to reach its potential, each player must be willing to

subordinate his personal goals to the good of the team.

Responsibility Sharing for Timely Execution

It was decided to distribute responsibilities among the team members for early completion of project.

Clear Communication & Proper Record Keeping

Communication guidelines were formulated and it was decided to keep all the finding of jobs carried

out in the APEX folder kept inside common OPERATION folder. Minutes or notes were posted from

team meetings or projects.

Safety our way of Life

The team ensured the safety of employees in the work place during the project implentation.Safety

talks, auditing ,supervision were effective.

AES Corporation 27/

Conclusion

Coming together is a beginning.

Keeping together is progress.

Working together is success.

Efficiency Improvement by Loss Minimization

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