Typical questions concerning equipment performance and their effect on
Power Plant heat rate
In a Combined Cycle Plant:
- How much power loss and poor heat rate can be attributed to dirty Gas Turbine compressor, improperly tuned control curve for the GT Inlet Guide Vanes, fouled tubes in HRSG, Feedwater preheater bypass valve passing, HPST Bypass valve passing, Steam Turbine eroded buckets, Condenser tube fouling, maldistribution of Cooling water to Condenser sections, etc.
- Is the selection of Inlet Air Filter optimized for pressure drop and filter efficiency?
- Are the calorific fuel measurements accurate for payment?
- How effective was that last GT compressor wash?
- Does the Condenser need cleaning this coming Inspection?
In a Conventional Steam Plant:
- How much power loss and poor heat rate can be attributed to Boiler radiant section water tubes fouling, low Feed Water heater outlet temperature, Air Heater leakage, poor soot blowing of Economizer section, Steam Turbine labyrinth seal passing, Condenser air leak, Cooling Water Pumps malperformance, etc.
- Why is the steam extraction temperature higher after Steam Turbine inspection overhaul?
- How much leakage is there in the Air Pre-Heater?
- What is the effect of heat load shift from radiant to convection section on overall plant efficiency?
- Is the FD Fan performing according to performance curve?
- How to continuously determine the heat rate of a coal fired steam plant without knowing the heating value of coal or having an accurate load cell to measure the coal flow?
ACTSYS’ Power Plant performance monitoring methodology
Our approach to identifying performance gaps from the new and clean condition of the equipment involves first-principles based thermodynamic simulations. Our in-house developed analysis methodology, using heat-balance models and tuned off-design models that reflect the performance of the equipment if it was a new and clean, allows us to quantify performance gaps. In this way appropriate corrective O&M activities can be planned to bridge performance gaps in the equipment.
Plant performance monitoring can be done periodically or in real-time through our Online Performance Monitoring System ACTSYS@ONETM that monitors plant performance gaps in real-time.
The chart below shows the deterioration in thermal efficiency of a combined cycle power plant over a period of time. The different component losses as quantified by performance monitoring are increasing and their relative values allow prioritised scheduling of corrective actions to be taken. With appropriate corrective maintenance on the degraded components, the thermal efficiency of the CCP plant was partially restored.
Outcome of ACTSYS’ Plant Performance Monitoring:
- Proactively pin-point plant sections and equipment with degraded performance
- Quantify degradation in terms of loss of overall efficiency in a non invasive manner
- Establish an efficiency-based predictive maintenance program to set and prioritise maintenance activities
This methodology complies with Singapore’s National Environmental Agency’s legislated requirements for Efficiency Performance Monitoring by Power Plants under the Energy Conservation Act.