Trender tools provide real-time and historical graphical interfaces for trending operational parameters to analyze equipment performance, diagnose faults, and aid in root cause analysis of issues. Combustion control is important to optimize the chemical reaction between fuel and oxygen while minimizing undesirable byproducts like nitric oxide and sulfuric acid. Online and offline optimization of combined cycle power plants utilizes mathematical modeling and real-time plant data to maximize efficiency, capacity, and profitability across varying operating conditions.

1. DISCUSSION ON MODERN TREND IN
MEASUREMENT, COMBUSTION
CONTROL, OPTIMIZATION OF
COMBINED CYCLE POWER PLANT
Kazi Asadullah Al Galib
Executive Engineer
(operation-1)
Shahjibazar 330MW CCCPP,
BPDB,Habiganj.

2. Trender Tool for Real-Time and historical Data showing

3. MARK VIE HMI OF GAS TURBINE

4. TRENDER TOOLS AND OPERATIONAL DATA
MEASUREMENT
The modern control systems (i.e. DCS-Siemens PCS7,Mark Vie etc.) have
wide range of tools for analyzing operational or process data in order to
diagnosis fault and trip as well as root cause analysis. Such as trender
tool, alarm system etc. Operational Data are measured for analyzing
healthy operational conditions and also to find faults.
Trender tool is the graphical interface for trending analog or digital
points. It is fully configurable and can auto-range the scale or set fixed
indexes. For accurate read out, the trend cursor displays the exact value
of all Points trended at a given point in time. It can be set up to mimic
strip Chart recorders, analyze the performance of particular parameters
over time or help troubleshoot root causes of issues. The Trender tool
Can be launched from the ToolboxST application or from the right-click
menu on the Cimplicity screen with the WorkstationST application.
Mark Vie trender tool is upgraded and best suited fault finding, root
cause analyzing technique than the previous Mark II, Mark IV, Mark V
system. This trender is much more advanced and effective tool than the
so called alarm panel, dos screen single parameter graph etc. of Mark II
and mark V system.

5. TRENDER TOOLS AND OPERATIONAL
DATA MEASUREMENT
 The Trender captures and displays trend graphs of variables in the
system. It can collect and display values in real time from controllers
and other data sources, and can display data collected by high-speed
coherent data collection systems, such as capture buffers and
dynamic data recorders. Trender also can display previously captured
data from a saved data file.
 Traces and data captured by Trender can be saved. Trender can be
opened from the ToolboxST* application or from the Windows® Start
menu. A Trender opened in the ToolboxST application is saved in the
system or a component. We can create as many Trenders as
necessary. If we open Trender from the Start menu, we can select
where to save the trend.

6. PREVIOUS CONTROL SYSTEM
FAULT FINDING
Previous tedious, ambiguous and erratic fault finding process
of viewing the alarm panel or just viewing the alarm list
which were incapable of root cause analysis.

7. TRENDER DATA SOURCE AND CURSOR
Two cursor individually select values
of time and together select ranges of
time. The cursor are used by a
number of functions in trender such
as trace statistics, user events, data
export.

8. LIVE TREND
Live trends are useful for monitoring systems in continuous operation. When
Trender contains live trends, it displays the incoming data onscreen in real time.
To add traces from a live data source
1. From the Edit menu, select Add Traces. When the welcome wizard displays,
click Next.
2. Select Live and click Next.
3. From the next page, select the data source of the variables.
4. From the next page, select the component with the variables to trend. When
running Trender from the Start menu, the next page requires you to first select
the system, then the component.
5. From the next page, select the time period to trend the data. For controller
data, this must be a multiple of the controller frame rate. Refer to section
Trender Frame Rate.
6. Click Add to display the Select a Variable dialog box and select variables to
trend. Click OK.
7. To add additional traces: from the Edit menu, select Add Traces. The Select a
Variable dialog box displays available variables for that component.
8. To remove traces: from the Edit menu, select Remove Selected

9. ADDING DATA INTO TREND

10. HISTORICAL TREND
To add traces from a historical source
1. From the Edit menu, select Add Traces. When the welcome wizard page displays, click
Next.
2. Select Historical and click Next.
3. From the next page, select the data source.
4. Enter the name of the workstation containing the historical data. The Data Source
field displays the type of historical data configured on the workstation.
5. Click Add to display the Select a Variable dialog box and select variables to trend.
Click OK and Finish.
Computer is the name of the computer configured with the Recorder or Historian
feature.
Data Source automatically populates to identify the type of historical data (Recorder or
Historian).
Server and Collection is the source of the data.
Server (Historian) specifies the OPC HDA server to use.

11. FAULT ANALYSIS USING TREND

12. FAULT ANALYSIS USING TREND

13. TREND OF COMBINED CYCLE UNIT IN DCS
Trender of DCS system showing more than twenty key parameters of different equipment of a
combined cycle power plants

14. TRENDER FEATURES AND
TOOLBAR

15. Trender of Mark Vie system showing multiple key parameters of different equipment of a

16. COMBUSTION CONTROL
What is Combustion?
Combustion is a process in which some material or fuel is burned.
Combustion of Natural Gas is a chemical reaction that occurs between
carbon, hydrogen & Oxygen. Whether it is striking a match or firing a jet
engine, the principal involved are the same. The reaction is
Since the Oxygen is contained in air, which also has Nitrogen, the
combustion reaction can be written as follows

17. COMBUSTION CONTROL
If the combustion process created only the reactions shown previously no
provision would be necessary for control. Unfortunately, other reactions
occur in which undesirable products are found
The water required in the reaction comes from the water of combustion.
The formation of Nitric oxide during combustion can be retarded by
reducing the temperature at which combustion occurs. Normal Combustion
temperatures ranges from 1871°C to 1927°C. At this temp. the volume of
Nitric oxide is about 0.01%. Which is dangerous for environment. If the
temp. is lowered below 1538° C the nitric oxide formation will be maxm. 20
perts per million(PPM) which is allowable.

18. COMBUSTION CONTROL
Minimum NOx formation is attained by injecting a noncombustible gas
around the burner to cool the combustion zone. It is known that oxides of
nitrogen may be notably reduced if the mixing of reactant takes place
before burning.
Cooling and sealing air to prevent NOx formation around
combustion chamber

19. COMBUSTION CONTROL
Sulfuric Acid is another common by-product of combustion. The reaction
is
The best method of eliminating sulfuric acid as a combustion product is to
remove sulfur from incoming fuel gas.

20. COMBUSTION CONTROL
 Control of a combustion process relies on several elements like combustion takes place
between fresh reactants supplied (at least for the fuel) by flow metering injectors. There
are two types combustion control.
1. Operating Point Control(OPC): The injection of fuel is regulated in order to maintain
certain flame parameters like equivalent ratio Φ, in a prescribed range of values.
2. Active combustion control (ACC): The controller output is used to modulate the flow
properties (fuel flow rate) to avoid or limit pressure oscillations, or to improve the
combustion characteristics.
3. In general GT air fuel ratio is around 100:1

21. COMBUSTION CONTROL
 Sensing technique: Generally two types of sensors are used for sensing
combustion system parameters.
1. Optical sensor
2. Solid state sensor

22. COMBUSTION CONTROL
In most cases the control of the equivalence ratio Φ of the mixture is crucial for
maintaining emissions at a low level. It has also been shown in the case of lean premixed
combustion that one of the physical parameters responsible for the rapid change of NOx
and CO with Φ is the flame temperature. Therefore, sensing of Φ or Tf would be directly
useful for control.
If one considers combustion of a fuel lean mixture of methane and air, the chemistry can
simply be modeled using a single step infinitely fast global reaction where α=2 and β=3.76

23. OPTIMIZATION OF POWER PLANT
 On line optimization processes for large utility plants is gaining
tremendous favor. Plant optimization is gaining importance with combined
cycle power plants as these plant s are operated over a wide range of power
in day to day operation. On line optimization may be defined as the place
where economics, operation and maintenance meet. Process optimization is
still only a pre-construction or pre-production exercise. Process
optimization and re-optimization “on the fly” can enable companies to
meet variations in market demand and maximize production efficiency and
overall profitability. When embodied in a modern integrated plant
environment, dynamic plant health assessment, process modeling and
process integration provide the means to augment plant reliability,
availability and safety with maximum capacity and flexibility.

24. MATHEMATICAL MODELING OF POWER
GENERATION OPTIMIZATION
According to the actual demand, the objective function included
outsourcing electric cost, self-generating cost, outsourcing power
coal cost, consumption gas cost, and comprehensive cost of steam
production and gas diffusion punishment cost system integrated
operation cost minimum. The objective function expression was as
follows:

25. Where symbols refers to:
𝐶
𝐶 ele
buy,𝑡 Price of outsourcing electricity in 𝑡 time point, RMB/kW⋅h
𝐶
𝐶 ele
gen,𝑚 Price of self-generation of device 𝑚, RMB/kW⋅h
𝐶
𝐶 coal Price of outsourcing coal, RMB/𝑡
gas
𝐶
𝐶
𝑖
𝑖 Price of 𝑖 gas, RMB/m3
ste
𝐶
𝐶
𝑚
𝑚 ,𝑘 Cost of 𝑘 steam production device 𝑚, RMB/𝑡
Gas
𝐶
𝐶
𝑖
𝑖 Punishment price of 𝑖 gas, RMB/m3
𝑓
𝑓 𝑚,𝑡 Consumption of equipment 𝑚 in 𝑡 time point, 𝑡/h
𝐹
𝐹 𝑚,𝑖,𝑡 Consumption of 𝑖 gas equipment 𝑚 in 𝑡 time point, m3/h
𝑄
𝑄 𝑚,𝑘,𝑡 Production quantity of 𝑘 steam equipment 𝑚 in 𝑡 time, 𝑡/h
𝐹
𝐹 Gas
𝑖
𝑖 ,𝑡 Emission capacity of 𝑖 gas in 𝑡 time point, m3/h
𝐸
𝐸
buy
𝑡
𝑡 Outsourcing electricity of 𝑡 time point, kW
𝐸
𝐸
gen
𝑚
𝑚 ,𝑡 Generation capacity of equipment 𝑚 in 𝑡 time point, kW

26. OPTIMIZATION OF POWER PLANT
On-line optimization process: The System
gathers data in real time. The data is gathered
from either the D-CS system or from the
control system. To ensure that performance
data is taken at a steady state condition, since
most models of the plant are steady state, the
system must observe some key parameters and
ensure that they are not varying. In turbines
parameters, such as turbine wheel space
temperature, turbine inlet temp., pressure etc.
should be observed to be constant. This data is
then checked for accuracy and errors removed.
New operational and performance maps are
then plotted and the system then can optimize
itself against an operational model. The
operational goal is to maximize the efficiency
of the plant at all loads, thus the new
performance maps, which show degradation of
the plant are then used in the plant model to
ensure that the control is at the right setting

27. OPTIMIZATION OF POWER PLANT
Off-line optimization process: Is an open loop control system instead of
closed loop system. It controls the plant settings, data is provided to the
operator so that he can make the decisions based on the findings of the
operational data. Off-line systems are also used by engineers to design
plants and by maintenance personnel to plan plant maintenance.

28. OPTIMIZATION OF POWER PLANT

29. QUESTIONS
Trend is used for?
Combustion occurs in presence of –
Nox formation occurs In lower combustion temp.