Condition monitoring

The other area of ecological diagnostic interests is the water, water basins and ice condition monitoring. 

Borhaug, J.E., and Mitchell, J.S., Applications of Spectrum Analysis to Onstream Condition Monitoring and Malfunction Diagnosis of Process Machinery, Proceedings of the 1st Turbomachinery Symposium, Texas A M University, 1972, pp. 150-162. 

The gas turbine is a complex system. A typical control system with hierarchic levels of automation is shown in Figure 19-3. The control system at the plant level consists of a D-CS system, which in many new installations is connected to a condition monitoring system and an optimization system. The D-CS system is what is considered to be a plant level system and is connected to the three machine level systems. It can, in some cases, also be connected to functional level systems such as lubrication systems and fuel handling systems. In those cases, it would give a signal of readiness from those systems to the machine level systems. The condition monitoring system... 

Implementation of advanced performance degradation models, necessitate the inclusion of advanced instrumentation and sensors such as pyrometers for monitoring hot section components, dynamic pressure transducers for detection of surge and other flow instabilities such as combustion especially in the new dry low NO combustors. To fully round out a condition monitoring system the use of expert systems in determining fault and life cycle of various components is a necessity. 

The new purchasing mantra for the new utility plants is life cycle cost and to properly ensure that this is achieved a total performance condition monitoring strategy is unsurpassed. 

Figure 19-8. A block diagram for an on-line condition monitoring system.

Maintenance practices are being combined more and more with operational practices to ensure that plants have the highest reliability with maximum efficiency. This has led to the importance of performance condition monitoring as a major tool in the operation and maintenance of a plant. Life cycle costs, rightly so, now drive the entire purchasing cycle and thus the... 

CONDITION MONITORING OUTPUTS Loss in Compressor Flow Through Put Loss in Compressor Pressure Ratio Fuel Cost Penalty Projected Increase in Fuel Cost After One Month Operation Surge Point Deterioration Trend and Anticipated Outage Date... 

Boyce, M.P., Gabriles, G.A., Meher-Homji, C.B., Lakshminarasimha, A.N., and Meher-Homji, F.J., Case Studies in Turbomachinery Operation and Maintenance Using Condition Monitoring, Proceeding of the 22nd Turbomachinery Symposium, Dallas, Texas. September 14—16, 1993, pp. 101-12. 

Boyce, M.P., Improving Perfoimiance with Condition Monitoring —Power Plant Technology Economics and Maintenance, March/April 1996, pp. 52-55. 

Boyce, M.P., and Venema, J., Condition Monitoring and Control Center , Power Gen Europe in Madrid, Spain, June 1997. 

Boyce, M.P., and Cox, W.M., Condition Monitoring Management-Strategy , The Intelligent Software Systems in Inspection and Life Management of Power and Process Plants in Paris, France, August 1997. 

Boyce, M.P., Condition Monitoring of Combined Cycle Power Plants, Asian Electricity July/August 1999, pp. 35-36. 

A new maintenance system is introduced based on the new mantra for the selection of all equipment Life Cycle Cost. This new system especially for major power plants is based on the combination of total condition monitoring, and the maintenance principles of total productive maintenance, and is called the Performance Based Total Productive Maintenance System. ... 

Figure 21-1. Total performance-based condition monitoring system.

Total condition monitoring (performance, mechanical, and diagnostic based). 

An autonomous maintenance program with total condition monitoring... 

Master plan development for PTPM. A master plan must be created. Total condition monitoring equipment should be designed, and equipment should be purchased. 

The old maxim if it ain t broke don t fix it is very applicable in today s machinery. A study conducted at a major nuclear power facility found that 35% of the failures occurred after a major turnaround. This is why total condition monitoring is necessary in any performance based total productive maintenance system and leads to overhauls being planned on proper data evaluation of the machinery rather than on a fixed interval. 

To determine if steady state conditions exist, the temperatures and pressures in the column can be tabulated to assure that they are reasonably unchanging. Laboratoiy analyses are usually too slow and expensive for checking lined out conditions. Monitoring reflux accumulator boiloff is often an effective way of noting concentration changes. Simply let a sample of the accumulator liquid boil at atmospheric pressure in a bottle with a thermometer inserted. This method is limited to light hydrocarbons and is not accurate enough for precision fractionation. 

There are two types of condition monitoring continuous and periodic. Continuous monitoring, as its name implies, examines measurements taken on a continuous basis. Periodic monitoring is based on measurements taken at regular time intervals. 

With the advent of computerized real-time systems, the distinction between continuous and periodic condition monitoring must be modified. Though technically periodic, a scanning system operating fast enough to protect against catastrophic failure is considered continuous. Most people consider one second or faster scan rates as continuous. A scan rate of one second is defined as monitoring each point once each second. 

Safety features (e.g. operation in explosive environments, alarm and condition-monitoring systems). 

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