Maintenance Management1

Maintenance Management in Power Plant and its effectiveness

Maintenance Management • • • •

Aimed at Optimum Plant Availability Maximising Capacity Utilization It is very critical in ABT regime Revenue Loss due to loss of Production is much higher than Maintenance Cost • Maximum resource utilization • Safety in work, equipment & environment

When to carry out maintenance? As per requirement

How to carry out ? Optimal way

Maintenance Management Knowledge & Awareness about Process & Equipments

Methods Tools & Technologies

Operation & Maintenance Requirements

Power Plant Systems & Equipments • Main Power Generation & Evacuation Systems & Equipments eg Boiler, Turbine, Generator,Generator Transformer and SWYD equipments (breakers, isolators) with instruments & control systems • Auxiliaries provided for safe & efficient operation of above main equipments & systems eg ID,FD, PA fans, BFP, CEP, excitation system, with instruments & control systems • Auxiliaries Plants installed to process & handle - Inputs like water, air and fuel (oil and coal) eg DM Plant,CHP - By product eg, AHP • Other systems for providing safety& suitable working environment eg Fire fighting system, AC, Air washer & Ventilation systems

Maintenance Concepts • • • • • •

Preventive Maintenance Corrective (Break down )maintenance Predictive Maintenance Opportunistic Maintenance Design-for/ Design-out Maintenance Health Usage Maintenance System

Preventive Maintenance • Planned Maintenance • Periodic inspection of Plant & equipment to prevent break downs before they occur • Repetitive Servicing, upkeep and overhaul of equipment • Adequate Lubrication, cleaning and House Keeping

Preventive Maintenance …contd. • Proper Identification of equipment • Adequate records covering Volume of Cost & Work • Inspection on Definite schedule • Use of Checklist by maintenance Person • Well qualified Maintenance Staff • Frequency and schedule is decided

Preventive Maintenance …contd. • Proper Procedure for fulfillment and follow up • Formal Procedure for planning and scheduling the work • Time standards for all maintenance works • Record of Equipment behaviour, failure History & inspection findings

Advantages of P.M. • • • • •

Greater Safety for workers Decreased Production Downtime Better Conservation of Assets Increased Life Expectancy Reduction in large scale & repetitive failures

Advantages of P.M. …contd. • Less standby equipment required • Better Spare Parts Control • Lower Unit Cost of production due to planned Maintenance • High Equipment Reliability

Disadvantages of P.M. • Many Times Maintenance is done well before it is needed • Increased cost of maintenance • Wastage of Resources

Corrective Maintenance • • • •

Often it is an emergency Maintenance becomes Repair Work Very High Loss of Production Downtime is not only of time taken to complete the job but also delay due lack of resources

Corrective Maintenance …contd. • • • • • •

High Maintenance Cost Low Availability Less effectiveness Unplanned Demand for Maintenance Less effectiveness Stressing and Dangerous work

Predictive Maintenance • This is Condition Based Maintenance • Bath Tub Curve Analysis • It is an strategy to carry out Preventive Maintenance at irregular Interval • Shut down is planned when resources are available and assessing Generation Schedule

Steps of Predictive Maintenance • Selecting Critical Machine for Programme • Establishing a Programme specifying the parts to be examined and method of examining them • Establishing danger limits of parameter e.g. Vibration, Temperature, sound etc. • Selecting Proper Examination Frequency

Steps of Predictive Maintenance • Importance of machine in process flow chart, availability of standby machine & operating condition • Finding Cost of examination & Overall cost of Failure & maintenance • Training of Inspectors and examiners • Establishing Schedule and budget of maintenace

Basic Methods of Monitoring • • • • • •

Visual Monitoring Vibration Monitoring Wear and Debris Monitoring Performance Monitoring Corrosion Monitoring Structural Integrity Monitoring

Advantages of CBM • • • • •

Increased Plant Availability Improved safety Reduced Maintenance Cost Better Resource Utilisation Experience leading to better specification for future Plant and Machinery

Limitations of CBM • Access of Probe not foreseen at design stage • Machine with in accessible parts • Parts which collapse suddenly due to failure

Types of Maintenance in Power Plant • Routine Maintenance • Preventive Maintenance • Scheduled Maintenance

• Break Down Maintenance • Diagnostic or Periodical Maintenance

Maintenance Management in TPP • • • • • • • •

Routine Maintenance Annual Overhaul Defect Rectification Work Request Scheduling & measuring of work Quality checks Production Calculation Different Management Ratio

Scope of Maint. Planning • • • • • • •

Over all Time and resource Planning Scheduling of Resources Issue and work Control Progress Monitoring Assessment of Productivity Reduce Plant Outages Condition Monitoring

Scope of Maint. Planning ….Contd. • • • • • • •

Monitoring Maintenance Cost Improve resource Utilisation Forecasting Target Dates Long Term Planning Short Term Planning Outage Planning Spare Parts Planning

Scope of Maint. Planning ….Contd. • To develop five years Rolling Plan • To develop Station Annual Plan • To Create Standard Data Bank for reference • Overhauling Management

Essential Inputs • • • •

Detailed and defined work Activity Standard work hour pattern and job duration Overall Time of outage Types of crafts men and skill required, their availability and productivity • Requirement of spares & Consumables, tools & Plants etc., their source of availability

Essential Inputs…….Contd. • • • • •

Mobilisation of resources within given time Progress Monitoring of work Quality Checks Feedback System Budget i.e. Finance • • • • •

Generation Budget Fuel Budget Spares Budget Manpower Budget Revenue Budget

Function of LTP • Compilation of Station Five year Rolling Plan • To Prepare and ensure all necessary arrangement for the year’s overhaul work programme • Produce, Distribute and Monitor major overhaul and control programme

Function of LTP …..Contd. • Operate Section of PTW system Before, during and after major overhaul • Custody of all licences of equipments under Indian Boiler Regulation Act, Indian Electricity Act, Indian Explosive Act and other safety Rules.

Function of STP • Development & Monitoring of Station work control system • Co-ordinate with maintenance sections and apprise them about plant reports • Information about proposed shut down if any, cooling, drains or constraints that might delay the availability of permit to start maintenance work

Function of STP

……Contd.

• Liasion with Operation department for the planning of defects rectification & apprise them about maintenance work and delay if any. • Allocation of station maintenance manpower to achieve short term and long term objectives • Maintain and Improve co-ordination between plant operation and maintenance • Plant Inspection Programme and progress • Scheduling based on inputs from long term planning

Function of STP

……Contd.

• To organise and provide service to daily plant meeting. • To maintain history of all equipments, Plant inventory cards and spare list cards • Updates and maintain work order cards • To maintain on-going lists of priority work and to ensure that short term plant overhaul programme is prepared and issued as required.

Handling Outage • • • • •

Daily Outage Meeting Work Progress Reporting system Manpower Reporting system Recommissioning checks Documentation of data

Changing Paradigm • Reliability Centered maintenance • Risk evaluation and Priortisation • Total Productive Maintenance