Sequence of Presentation
1.Why Process Control?
2 What to Control?2.What to Control?
3.Role of Sensors and Instruments
4.Modes Of Control Systems
5.Basics of Feedback Control Systems5.Basics of Feedback Control Systems
6.Examples of Servo Control Systems
7.Conclusions
1. Why Process Control ?
1.Safety of Equipment and Personnel
2 Productions Specification of quality & 2.Productions Specification of quality & quantity
3 Operational Constraints 3.Operational Constraints
4.Observe Environmental and Country LLaws
5.Economics
Control Objectives
1. Safety of Equipment &
Give example
q ppersonnel
2. Production Specification of
VaporProduct
T1 T5
T6 PC
quality & quantity
3. Operational
T1
F1
T2
T4
T5
T3 L1
Feed
Constraints
4. Environmental Regulations
LiquidF3F2
A15. Economics
LiquidproductSteamProcess
fluid L. Key
A1
Safety of Equipment & Personnel
1. Safety of Equipment & personnel
High pressurein drum is dangerous
VaporT6 PCpersonnel
2. Production Specification of quality &
VaporProduct
T1 T2 T5
T6 PC
Feedquality & quantity
3. Operational Constraints
F1
T2
T4 T3 L1Constraints
4. Environmental Regulations
5 E iLiquid
P
F3F2A15. Economics productSteamProcess
fluid L. Key
Control Objectives
1. Safety of Equipment &
Give example
q ppersonnel
2. Production Specification of
VaporProduct
T1 T5
T6 PC
quality & quantity
3. Operational
T1
F1
T2
T4
T5
T3 L1
Feed
Constraints
4. Environmental Regulations
LiquidF3F2
A15. Economics
LiquidproductSteamProcess
fluid L. Key
A1
Safety of Equipment
1. Safety of Equipment &
lVaporT6 PC
No flow could damage the pump
personnel
2. Production Specification of
lit &
Product
T1 T2 T5F dquality &
quantity
3. Operational Constraints
F1 T4 T3 L1
Feed
Constraints
4. Environmental Regulations Liquid
d tSteamProcess
F3F2A1
5. Economics productSteamProcessfluid L. Key
Smooth Production Rate
1. Safety of Equipment &
Always keep the production rate smoothq p
personnel
2. Production Specification of
VaporProduct
T5
T6 PCrate smooth
quality & quantity
3. Operational
T1
F1
T2
T4
T5
T3 L1
Feed
Constraints
4. Environmental Regulations F3F2
L1
5. Economics LiquidproductSteamProcess
fluid L. Key
A1
Quality Assurance
1. Safety of Equipment &
VaporT6 PC
Give Example
personnel
2. Production Specification of
VaporProduct
T1 T2 T5
T6 PC
quality & quantity
3. Operational
T1
F1
T2
T4
T5
T3 L1
Feed
Constraints
4. Environmental Regulations
LiquidF3F2
A15. Economics
LiquidproductSteamProcess
fluid L. Key
A1
Quality Assurance
1. Safety of Equipment &
Achieve L.Key by adjusting the heatingEquipment &
personnel
2. Production Specification of
VaporProduct
T6 PCthe heating
Specification of quality & quantity
3 Operational
T1
F1
T2
T4
T5
T3 L1
Feed
3. Operational Constraints
4. Environmental Regulations
F3F2
L1
Regulations
5. EconomicsLiquidproductSteamProcess
fluid L. Key
A1
Observe Environmental and Other Regulations
1. Safety of E i t &
Never release hydrocarbons
Equipment & personnel
2. Production S ifi ti f
VaporProduct
T5
T6 PCy
to atmosphere
Specification of quality & quantity
3 Operational
T1
F1
T2
T4
T5
T3 L1
Feed
3. Operational Constraints
4. Environmental Regulations Li id
F3F2Regulations
5. EconomicsLiquidproductSteamProcess
fluid L. Key
A1
Economics
1. Safety of E i t &
Give Example
Equipment & personnel
2. Production S ifi ti f
VaporProduct
T6 PC
Specification of quality & quantity
3 Operational
T1
F1
T2
T4
T5
T3 L1
Feed
3. Operational Constraints
4. Environmental Regulations
F3F2
T3 L1
Regulations
5. EconomicsLiquidproductSteamProcess
fluid L. Key
A1
Economics
1. Safety of Equipment & personnel
2. Production Specification of
Give Example
quality & quantity
3. Operational C iConstraints
4. Environmental Regulations
5. Economics
2. What to Control ?
1.The Influence of External Disturbances (Suppress Them)Disturbances (Suppress Them)
2.Ensure Stable Operation
(Avoid Unsteady State)
3 O ti i d O ti 3.Optimized Operation
(Control Operating Costs)(Control Operating Costs)
Suppress the Influence of External Disturbances
Disturbances?
Ensure Stable Operation
Ensure Stable Operation (cont’d)
Optimized Operation (online)
Potential Stochastic Gains through effective Process Control
When we control a process, we reduce the variability.
Potential Stochastic Gains through effective Process Control (Cont’d)
Variability is moved from controlled to manipulated variable!
Potential Stochastic Gains through effective Process Control (Cont’d)
What statistics l l tcan we calculate
from this data?
How do we relate variability to process performance?performance?
Potential Stochastic Gains through effective Process Control (Cont’d)
Process performancepefficiency, yield, production rate, etc. It measures performancemeasures performance for a control objective.
Calculate the processperformance using the distribution not thedistribution, not the average value of the key variable!
Examples of feedback system
A typical instrument has three components:
3. Role of Sensors and Instruments
A typical instrument has three components:
A SensorA SensorA ModifierA Display (Or transmitting arrangement)
Sensors feel the condition and originate the i l f ll d b difi ti d signal followed by modification and
amplification for effective display or transmission.
Instruments are the eyes of engineer/
Comment on Sensors and Instruments
Instruments are the eyes of engineer/ operator that can see & feel the intense process variable inside the vessels
Accordingly the measurements should be reliable and as close to actual condition as reliable and as close to actual condition as possible with reasonable costs.
Process control go hand in hand “If you cannot measure you cannot control!”
Example of Temperature Control (Heat exchanger)
4. Modes of Control Systems
Feedback Control Systems (Regulatory)Feedforward Control Systems(Servo, Tracking)Sequential Control SystemDistributedIntegratedIntegrated
Modes of Implementation
PneumaticElectronicDigital
Basics of feedback control system
Example of Composition Control
Examples of feedback system
Examples of feedback system
Where is Control Done?
Examples of feedback system
Examples of feedback system
Control System Implementation
Analog and local ControlAnalog and local Control
Microprocessor based Distributed ControlMicroprocessor based Distributed Control
Field Bus based Distributed Control System(State of art with ever growing capabilities
and features!)
Control Systems Implementations In Industry
Control Systems Implementations In Industry
Control Systems Implementations In Industry