Craig Rebuli BU Manager Monitoring and Control Martec South Africa

Transcription

1 Craig Rebuli BU Manager Monitoring and Control Martec South Africa

2 Introduction Advantages and disadvantages of monitoring your assets?

3 Asset Management What is asset management about? Get the most out of your assets People and Machines The practice of managing assets to achieve the greatest return - Wikipedia

4 How do you get maximum return Efficiency ɳ = power out / power in (Maximise your output) Cost effective Minimal down time Minimal input maximum output Lower maintenance costs

5 Plant availability (720 production hours available per month) Planned Maintenance (Typically 50 hrs/month) (Good installation, Lean maintenance) Plant Availability Production time Breakdowns (Typically 50 plus hours/month) (Reduce unplanned repairs) Other (Typically 20 plus hrs/month) Product change Material shortages No operator No electricity Other (No material/pow outages/change of prod Plant Runtime (Typically Unscheduled > 600 of 720 hours) maintena (Increase the no. of run hours) From experience many Scheduled maintenanc plants operate below 80% runtime, leaving much room for improvement Purpose : Benchmark and Improve

6 Various approaches to maintenance Regressive maintenance approach 1. Run to failure - no or little maintenance (Most expensive approach in the long run) (Estimated to be about 4-6 times the cost of condition based maintenance) Reactive/Corrective maintenance approach 2. Unplanned maintenance breakdowns Preventative maintenance approach 3. Time based maintenance (monthly, run-hours, annual) condition may be good** Predictive maintenance approach (Proactive) 4. Condition based maintenance. (Maintenance planned as and when required) (Continuous and/or periodic measurement)

7 Asset Performance The Maintenance - Monitoring loop Maintenance procedure Goal: Planned maintenance Condition monitoring Periodic - handheld (monthly/quarterly) (Not scalable) Continuous online, web based Maintenance request Death by data report - Seldom giving a definite prognosis, - Often not responded to/taken seriously On-line Client receives near-real-time alarms On the fly updated analysis & solutions Expert telephonic advice (24x7) Analysis/Diagnostics Manual analysis & reporting (Not scalable) Automated alarms Automated analysis & reporting Exceptions - human oversight

8 Underlying Principles Most failures are not prevented because it is not known that there is an incipient fault (or developing defect) Often it is not enough to only know that there is a developing defect To prevent failures, you must also know The nature of the defect The location of the defect The severity and rate of progress of the defect

9 Underlying Principles Usually the failure itself is a relatively minor problem The real cost comes from Collateral damage Loss of production and revenue Loss of customer goodwill, etc

10 Underlying Principles Key Objectives: 1. Detect defects at the earliest possible stage in the most reliable and economical way 2. Facilitate diagnostics and prognostics for decision making

11 Predictive maintenance Benefits of Predictive Maintenance Maintenance costs reduced by 50% Unexpected failures reduced by 50% Repair time reduced by 60% Parts inventory reduced by 30% MTBF increased by 30% Uptime increased by 30% Source: Plant Engineer's Handbook R Keith Mobley 2001

12 Types of monitoring Offline Online Periodic Continuous Web based

13 What plant assets are monitored

14 Plant Monitoring Rotating Machines Phase Vibration Current signature Partial discharge(pd) Oil analysis Shaft voltage Ultrasound Temperature

15 Plant Monitoring Transformers Oil analysis Ultrasound Infra red Temperature Vibration Cables Cablewise RF sniffer

16 Plant Monitoring Boilers Acoustics Switch gear Ultrasound Infra red Gas analysis

17 Cost / benefit ratio Monitoring is all about cost benefit ratio Even small assets can be critical to the plant operation

18 Questions?