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1Copyright 2018 by CyboSoft 1

Flare Control System DesignFlare Control System DesignFor Refinery Flares to Comply with RSR 63.670 RulesFor Refinery Flares to Comply with RSR 63.670 Rules

www.cybosoft.comwww.cybosoft.comTel: 916Tel: 916--631631--6313, [email protected], [email protected]

Dr. George S. Cheng, CyboSoftDr. George S. Cheng, CyboSoft

April 2018

For a Cleaner Earth

2Copyright 2018 by CyboSoft

EPA Targeted Illegal Air Emissions

From www.EPA.gov


Key Limits and Monitoring

EPA and RSR RegulationsEPA and RSR RegulationsVent GasVent Gas NHVvgNHVvg >= 300 Btu/>= 300 Btu/scfscf. (This is in Subpart A). (This is in Subpart A)Combustion ZoneCombustion Zone NHVczNHVcz >= 270 Btu/>= 270 Btu/scfscf..Combustion Efficiency (CE) > 96.5%.Combustion Efficiency (CE) > 96.5%.Net Heating Value Dilution Parameter (Net Heating Value Dilution Parameter (NHVdilNHVdil) > 22 Btu/sq. ft).) > 22 Btu/sq. ft).

RealReal--Time Monitoring SystemTime Monitoring SystemThe new RSR 63.670 rule is based on a quadratic 15The new RSR 63.670 rule is based on a quadratic 15--min datamin datablock. (Minute 0 to 15, 15 to 30, 30 to 45, and 45 to 60). If flblock. (Minute 0 to 15, 15 to 30, 30 to 45, and 45 to 60). If flarearestarts at minute 12, that data point collected is still countedstarts at minute 12, that data point collected is still counted forforthe first 15the first 15--min block.min block.An online calorimeter such asAn online calorimeter such as HobreHobre and/orand/or ExtrelExtrel is needed tois needed tomeasure the vent gas heating value,measure the vent gas heating value, NHVvgNHVvg..Proper gas and steam flow sensors are needed to calculate andProper gas and steam flow sensors are needed to calculate andstorestore NHVczNHVcz andand NHVdilNHVdil as part of the monitoring system.as part of the monitoring system.


Combustion Zone Heating Values

For Steam Assisted FlaresFor Steam Assisted Flares

For Perimeter Assisted FlaresFor Perimeter Assisted Flares

NHVcz – NHV of Combustion Zone, NHVvg – NHV of Vent Gas.

Qvg – Volumetric Flow of Vent Gas, Qs – Volumetric Flow of Steam.

Qa - Volumetric Flow of Premix Air.

(Btu/scf)

(Btu/scf)


Net Heating Value Dilution Parameter

For Perimeter Assisted Flares OnlyFor Perimeter Assisted Flares Only

Diam – Diameter of flare tip for flare vent gas flow,

NHVvg – NHV of Vent Gas,

Qvg – Volumetric Flow of Vent Gas,

Qa – Volumetric Flow of Premix Air,

Qa2 – Volumetric Flow of Perimeter Air.

EPA does not tell you how to comply. For control, we need to usereal-time data and trends. 15-min block data is not sufficient.


Flare NHVcz and NHVdil Control

Why AreWhy Are NHVczNHVcz andand NHVdilNHVdil Control DifficultControl DifficultThe vent gas flow can change widely and quickly,The vent gas flow can change widely and quickly,The heating value in vent gas can change widely and quickly,The heating value in vent gas can change widely and quickly,The assist air and/or steam needs to have a proper ratio to theThe assist air and/or steam needs to have a proper ratio to thetotal amount of vent gas and its contained heating value, wheretotal amount of vent gas and its contained heating value, whereNHVczNHVcz andand NHVdilNHVdil are good indicators,are good indicators,Nitrogen is often used as purge gas to maintain positiveNitrogen is often used as purge gas to maintain positivepressure in the vent pipe, making the process more complex,pressure in the vent pipe, making the process more complex,There are large and varying time delays in the heating valueThere are large and varying time delays in the heating valuecontrol loops, especially for thecontrol loops, especially for the NHVczNHVcz loop, andloop, andThe heating value process is extremely nonlinear in differentThe heating value process is extremely nonlinear in differentoperating conditions.operating conditions.

PID-based or model-based closed-loop heating value controlsystem are difficult to design, commission, and maintain.


MFA Flare Heating Value Control


MFA Control of Vent Gas Heating Value

Heating Value PV (Btu/scf) - Green

Vent Gas Flow - Grey

Controller OP (0-100%) - Red

EPA Limit = 300 Btu/scf - Yellow

Heating Value SP = 350 Btu/scf - Blue


MFA vs PID Heating Value Control


MFA Control for Steam Assisted Flares


Control for Steam Assisted Flares

Control of Vent Gas Heating Value,Control of Vent Gas Heating Value, NHVvgNHVvgIt is important to automatically controlIt is important to automatically control NHVvgNHVvg so that it is aboveso that it is above300 Btu/300 Btu/scfscf. If. If NHVvgNHVvg is not under control,is not under control, NHVczNHVcz will have nowill have nochance to comply with the 270 But/chance to comply with the 270 But/scfscf limit.limit.

Control of Steam Flow, QsControl of Steam Flow, QsNHVczNHVcz is proportional tois proportional to NHVvgNHVvg relating to the volumetricrelating to the volumetricsteam flow Qs. To assuresteam flow Qs. To assure NHVczNHVcz > 270 Btu/> 270 Btu/scfscf., Qs must be., Qs must beeffectively controlled. (See Formula (1) on Page 7)effectively controlled. (See Formula (1) on Page 7)Too low of Qs will result in a smoking flare which is prohibitedToo low of Qs will result in a smoking flare which is prohibited..Too high of Qs will causeToo high of Qs will cause NHVczNHVcz < 270 But/< 270 But/scfscf..

Control of Combustion Zone Heating Value,Control of Combustion Zone Heating Value, NHVczNHVczThe MFA Combustion Zone Heating Value Control SystemThe MFA Combustion Zone Heating Value Control Systemuses an Antiuses an Anti--delay MFA controller to deal with large anddelay MFA controller to deal with large andvarying time delays.varying time delays.


MFA NHVcz & NHVvg Cascade Control


Online Btu Sensor & Poor Steam Control


Slow GC Data & Good Steam Control


Slow GC Data & Poor Steam Control


MFA Control for Air Assisted Flares


Model-Free Adaptive (MFA) Control

No process models;

No identification;

No controller design;

No manual tuning.

MFA controlsMFA controlscomplex systemscomplex systems

Control ObjectiveControl ObjectiveController to produce

OP to force PV to track SPor minimize e(t).

SISO

MIMO


Inside MFANo ModelNo Model

RobustRobust

SpeedSpeed

Weights are updated to helpminimize e(t).

Provides much widerrobust range than PID.

Controls immediately, nowaiting on model building.

AdaptiveAdaptive

A neural network is part of the MFAcontroller.


Running CyboCon Demo


MFA Advantage & Suitability

Item PID MBC MFA

General purpose YY NN YY

Adaptive NN Y/NY/N YY

No process model YY NN YY

No identification YY NN YY

No controllerdesign

YY NN YY

No manual tuning NN YY YY

Controls complexsystems

NN YY YY

Easy to use andmaintain

NN NN YY

Amount of process knowledge

Application Suitability

PIDModelBased

ControlPro

cess

Var

iatio

n

BlackBox

WhiteBox

GreyBox

MFA is suitable for Grey boxproblems, where the process hasuncertainties including load,fuel, and dynamic changes, etc.

PIDPID –– one algorithm for all, MBCone algorithm for all, MBC –– one algorithm fits one system,one algorithm fits one system,MFAMFA –– one algorithm solves one control problem.one algorithm solves one control problem.


MFA Controllers at a Glance

Controls pH processes with large time delaysControls pH processes with large time delaysAntiAnti--delay MFA pHdelay MFA pH

Controller NameController Name Control Problems SolvedControl Problems Solved

SISO MFASISO MFA Controls a wide variety of processesControls a wide variety of processes

MFA (Turbo)MFA (Turbo) Adapts, no manual tuning required.Adapts, no manual tuning required.

MIMO MFAMIMO MFA Controls multivariable processesControls multivariable processes

Nonlinear MFANonlinear MFA Controls extremely nonlinear processesControls extremely nonlinear processes

MFA pHMFA pH Controls pH processesControls pH processes

AntiAnti--delay MFAdelay MFA Controls processes with large time delaysControls processes with large time delays

MFA Flare HeatingMFA Flare HeatingValue Control SolutionValue Control Solution

Specially designed to deal with nonlinear,Specially designed to deal with nonlinear,varying time delays, and large disturbances.varying time delays, and large disturbances.

Feedforward MFAFeedforward MFA Deals with measurable disturbancesDeals with measurable disturbances

Robust MFARobust MFA Forces PV to stay within its boundsForces PV to stay within its bounds


CyboLink OPC Client Software Screens

Signal Wiring of CyboCon to DCS

The Switch block in PLC is to switch between MFA and PID.

An MFA Button is added to the HMI screen so that the operator caneasily switch the system between MFA, PID, or manual control.


Recognized as Industry Leader

Prestigious awards validate the impact of MFA to the industry.Prestigious awards validate the impact of MFA to the industry.

CyboCon CEwith a GE Box


MFA in Siemens Adaptive BAS

APOGEEBAS

MFA in SiemensMFA in Siemens’’ APOGEE BuildingAPOGEE BuildingAutomation System (BAS)Automation System (BAS)

Control supply air temp, return air temp,Control supply air temp, return air temp,pressure, flow, and humidity of AHU.pressure, flow, and humidity of AHU.Easy configuration for various buildings,Easy configuration for various buildings,climate zones, and varying conditionsclimate zones, and varying conditions……Controller manual tuning not required.Controller manual tuning not required.

Benefits and ImpactBenefits and ImpactUserUser -- better comfort, energy savings.better comfort, energy savings.

SiemensSiemens -- technician time savings, and sharpertechnician time savings, and sharpercompetitive advantage.competitive advantage.

Since 2006, about 100,000 new MFA controllers areSince 2006, about 100,000 new MFA controllers arelaunched by Siemens every year.launched by Siemens every year.


MFA in Canrig DrillSmart System

MFA Canrig’s DrillSmart ControlMFA Canrig’s DrillSmart ControlSystemSystem –– MFA in NI cRIOMFA in NI cRIO

MFA controls Rate of Penetration, Weight onMFA controls Rate of Penetration, Weight onBit, and Differential Pressure.Bit, and Differential Pressure.For horizontal and lateral drilling for differentFor horizontal and lateral drilling for differentrigs under varying operating conditions.rigs under varying operating conditions.Controller manual tuning not required.Controller manual tuning not required.

Benefits and ImpactBenefits and Impact

Safer, more efficient oil&gas well drilling.Safer, more efficient oil&gas well drilling.Much easier lateral drilling operations.Much easier lateral drilling operations.

Sharper competitive advantage.Sharper competitive advantage.

Major impact to world oil&gas explorationMajor impact to world oil&gas exploration

In 2017, about 800 systems are in operation.In 2017, about 800 systems are in operation.


An off-gridCyboInverter canconnect to 4 x 300Wsolar panels directlyand produce up to1.2KW AC power torun 9000 to 12000Btu Inverter-Air-Conditioners, withno batteries.

Off-Grid Solar Air Conditioning

A 4-channel CyboInverter is a 4-input-1-output high-speed nonlinearsystem with varying inputs. Very difficult to control using PID ormodel based control methods. MFA is the enabling tech for this.


Good Approaches and Bad IdeasCyboSoft’s Technical ApproachesCyboSoft’s Technical Approaches

Flares can all be different, but our solution is more generalizeFlares can all be different, but our solution is more generalized ford foreasier implementation and maintenance.easier implementation and maintenance.Systematic approach to address various challenges.Systematic approach to address various challenges.Standard platform: DCS, OPC, Modbus, CyboCon MFA software.Standard platform: DCS, OPC, Modbus, CyboCon MFA software.Specially designed MFA controllers with simple parameters.Specially designed MFA controllers with simple parameters.Easy to install, commission, and maintain.Easy to install, commission, and maintain.

Ideas That Can Cause the RSR Project to FailIdeas That Can Cause the RSR Project to FailCounting on slow Btu data by GC, playing with 15Counting on slow Btu data by GC, playing with 15--min block data.min block data.Believing the Btu rich vent gas does not need good control.Believing the Btu rich vent gas does not need good control.Designing subDesigning sub--systems such as the steam control systemsystems such as the steam control systemindividually without considering a total system solution.individually without considering a total system solution.Assuming the PID controllers in DCS are good enough.Assuming the PID controllers in DCS are good enough.Leaving no time nor budget, hoping magic happens at the last minLeaving no time nor budget, hoping magic happens at the last min..


RecommendationsWhy Use MFA Flare ControlWhy Use MFA Flare Control

ModelModel--Free Adaptive (MFA) control is a proven controlFree Adaptive (MFA) control is a proven controltechnology that has been deployed widely since 1997.technology that has been deployed widely since 1997.MFA flare control system is delivered in standard platforms.MFA flare control system is delivered in standard platforms.Compliance with RSRCompliance with RSR--63.670 rules in all operating conditions.63.670 rules in all operating conditions.Substantial amount of natural gas and steam savings.Substantial amount of natural gas and steam savings.Getting the job done quickly once and for all.Getting the job done quickly once and for all.Flexible business arrangements with quick ROI.Flexible business arrangements with quick ROI.

What to Do NextWhat to Do NextStakes are high, rules are serious, and deadline is approaching.Stakes are high, rules are serious, and deadline is approaching.Do not underestimate the technical difficulties.Do not underestimate the technical difficulties.Not worth fighting this alone while effective products andNot worth fighting this alone while effective products andsolutions are available.solutions are available.Leave sufficient time and budget. If needed, we are here to helpLeave sufficient time and budget. If needed, we are here to help..


CyboSoft Offerings

Flare Process Modeling and Control Simulation SoftwareFlare Process Modeling and Control Simulation SoftwareRun realRun real--time flare process model and control simulation as atime flare process model and control simulation as atraining tool for this complex process. Help design your controltraining tool for this complex process. Help design your controlsystem or see how MFA control solution works.system or see how MFA control solution works.

MFA Flare Control SolutionMFA Flare Control SolutionMFA flare control systems can deal with all the challenges inMFA flare control systems can deal with all the challenges incontrollingcontrolling NHVvgNHVvg,, NHVczNHVcz, CE, and, CE, and NHVdilNHVdil so the flare canso the flare cancomply with EPA limits in all operating conditions.comply with EPA limits in all operating conditions.Use CyboCon MFA control software running in a PC andUse CyboCon MFA control software running in a PC andinterface to an existing DCS through OPC orinterface to an existing DCS through OPC or ModbusModbus, etc., etc.

Flare Control Consulting and OnFlare Control Consulting and On--Site CommissioningSite CommissioningConsulting for building an effective control system to complyConsulting for building an effective control system to complywith EPA RSR 63.670 rules. Control system design, partswith EPA RSR 63.670 rules. Control system design, partsselection, onselection, on--site commissioning, training, and services.site commissioning, training, and services.


Founded in 1994, a technologycompany offering specialty softwareproducts and solutions.

The leader in control technologyserving the worldwide process control,building control, and equipmentcontrol markets.

Won Frost & Sullivan 2007 NorthAmerican Tech Leadership Award.

Rancho Cordova, Calif.

Our vision and missionOur vision and mission

CyboSoft

Provide control tech and products to address urgent market needsProvide control tech and products to address urgent market needs..

Help address the “critical threats” and contribute to the socieHelp address the “critical threats” and contribute to the society.ty.

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