ELTRX POD (Performance Optimization and Diagnostics) Module
Power plants usually do not operate under test design conditions. Deviations in heat rates and efficiencies from their ideal values and variations in process parameters adversely impact overall plant performance. Any plant operating with incorrect operational set points will impact the efficiency and heat rates, resulting in burning extra fuel for meeting station demand. A US Environmental Protection Agency study reveals that adoption ofÂ advanced optimization technologies for heat rate optimization improves boiler efficiency by 1.5% while intelligent soot blowing techniques help enhance it by up to 0.9%. Increasing equipment life and reducing carbon footprint are other factors that drive the implementation of an advanced optimization solution.
ELTRIX Plant Performance Optimization & Diagnostics (POD) module provides a number of optimization and diagnostics functionalities for gas fired and coal fired power plants. When combined with ELTRIX Plant Performance Management (PPM) module, it offers a complete solution for Performance Analysis, Diagnostics and Optimization (PADO). The various sub-modules of POD include:
Plant Performance Optimization
- System Performance Optimization (SPO)
- Boiler Performance Optimization (BPO)
- Soot Blower Optimization (SBO)
- Combustion Process Optimization (CPO)
Â Plant Performance DiagnosticsÂ
- Plant Alarm Diagnostics (PAD)
- Water Chemistry Management (WCM)
The SPO module analyzes and optimizes the performance of various sub-systems in power plants such as boilers, turbines, condensers, feed heaters, de-aerators and auxiliary equipment. SPO optimization maximizes thermal efficiency, lowers emissions, reduces total maintenance cost and improves reliability. The SPO module works in conjunction with other modules such as the performance monitoring module, soot blower optimization module and boiler performance optimization module.Â
Boiler Performance Optimization consists of Combustion and Soot Blower Optimization. The key features of Boiler Performance Optimization module are:
- Continuously tracks the real time efficiency of the boiler system and compares it with the expected boiler efficiency.
- In case ofÂ deviations, the system analyzesÂ the root cause of such deviations
- Recommends the optimized set points to improve the boiler efficiency and optimize the fuel consumption.
- Reduces NOX emissions, while adhering to CO limits
In order to maximize operational efficiency, the fuel consumption rate should match with the generator steam demand. To achieve this state, air and fuel flow must be controlled. Combustion optimization module optimizes the amount of air required for combustion based on fuel properties. Based on an assessment of the stoichiometric condition, the CPO module adds excess air required for complete combustion.
The objectives of combustion optimization are:
- Controlling NOx to a desired set point
- Balancing of combustion
- Maximizing boiler efficiency
Soot blowing is a boiler cleaning procedure which improves the unitâ€™s heat rate. SBO module is specifically designed and developed to compute the level of slag / soot formation in each heat transfer section of the boiler. This module further conveys to the operator section-wise requirements of optimal soot blowing. The benefits of SBO are
- Determines boiler cleaning actions dynamically
- Directs existing soot blowing control systems to take action in real-time to best meet the unitâ€™s key performance indicators.
- Works in conjunction with existing soot blowing control and instrumentation system.
- Developed by using adaptive modeling and expert rules thereby improving accuracy
- Initiates strategic soot blowing sequences to minimize heat rate and process steam loss.
- Calculates the actual heat transfer coefficient of each heat exchanger continuously
The Alarm Diagnostic module plays a vital role in monitoring the different alarms generated in the control system along with all the process values.
Once an alarm is triggered, the root cause analysis program is activated and the cause of the alarm is identified by traversing the diagnosis decision tree.
The alarm diagnostics module involves the following three steps:
- Root Cause Analysis (RCA) in case of process abnormality.
- Decision support (DS) on corrective actions for process operation and maintenance.
- Time-critical DS for alternative actions.
An adaptive algorithm is used for root cause analysis of alarms. Once the alarm is triggered, the algorithm identifies the root cause of the event by exploring the defined list. This is done by evaluating a set of premises associated with the alarm condition and their influence over the event. The most likely causes for the alarm are listed with systemâ€™s confidence level (reliability index). After inspecting the unit, the algorithm identifies the actual causeÂ to the system. Based on the actual cause of alarm, the system reassigns the confidence measures and correlations between alarms, causes and their premises. With this adaptive nature, the root cause prediction by the system is expected to improve its accuracy over a period of time.
Corrosion in steam generators is an area ofÂ significant concern to both manufacturers and users. A primary objective of water chemistry management module is to avoid internal boiler tube corrosion. This module helps expand the life of boiler parts, decreases consumption of chemical dosing, minimizes scale formation in boiler tubes, and prevents carryover of impurities to the turbine.
The system monitors the water and steam quality in different sections of the steam generation cycle. Based on the inputs received after monitoring water and steam, WCM module diagnoses the causes of upsets in steam generator cycle chemistry and suggests corrective actions.