Introduction to PEF3006 Process Control · 2018. 8. 5. · Introduction to PEF3006 Process Control...

Introduction toPEF3006 Process Control

By Finn Aakre Haugen, PhD, Docent(finn.haugen@usn.no)

105 Aug 2018. PEF3006 Process Control.

USN.

205 Aug 2018. PEF3006 Process Control. USN.

Course organization:

• Lectures - in classroom and on video

• Theoretical exercises

• Labs and simulations (compulsory)

- individual and in groups

• Written exam counting 100%

- without aids but with formula list known in advance

305 Aug 2018. PEF3006 Process Control.

USN.

Course contents ...

PID feedback control

405 Aug 2018. PEF3006 Process Control.

USN.

(PID = Proportional + Interal + Derivative)

Demo:

Simulation of a temperature control system of a liquid tank

(This tank may be a biogas reactor.)

505 Aug 2018. PEF3006 Process Control. USN.

Cascade control - several PID loops inside each other

605 Aug 2018. PEF3006 Process Control. USN.

Feedforward control - using measured environmental

variables for control

705 Aug 2018. PEF3006 Process Control.

USN.

MPC (Model-based Predictive Control)

- using simulations into the future to find the optimal

control signal

Timetk tk+1 tk+Ntk+(N-1)

y (predicted by model)

uopt (predicted)

d (assumed)

x(tk) (known from

meas or estimator)

Prediction horizon (N+1 points of time)

Main aim is to calculate

uopt(tk) = uopt(1)= ?

Present

point of

time Future

ysp (known)

Ts

y(tk) (known from

meas or estimator)

d(tk) (known from meas

or estimator or assumed)

x (predicted by model)

805 Aug 2018. PEF3006 Process Control. USN.

Plant-wide control structures

- to control flow, material (inventories or accumulated

amounts of solids, liquid and gas) and temperature in

industrial plants

Nitric acid plant with control system (simplified):

Tank T1

Mixer

M1

Process

water

Reactor

R1

Compressor

K1

NH3

FT

2FFC

1

LC

1

LT

1

PT

1

PC

1

Evaporator

E1

Cold

water

Liquid

Gas

Ammonia

(liquid)

LT

2

LC

2

Condenser C1

LT

3

LC

3

O2

890 oC

NO + H2O

Raw

nitric

acid

HNO3

H2OAbsorber

A1

N2 and NOx

Liquid (acid)

Gas

Shaft 1

Turbine/

generator

TG2

Tail gas

Liquid down

Gas upHeater H1

Air with NOx

FC

3

FT

3

Feed:

Gas

V4

Valve

V1

V2

V3

V5

P1

Manual

setpoint

adjustment

QT

1

NH3

Ammonia

(gas)

Feed:

ST

1

SC

1Air

Turbine/

generator

TG1

Steam

Steam

Steam

drum

D1

Water

Gas

Gas

Specified

Amm./Air

ratio

Liq.

Lab

analysis

Production rate

setpoint

Meas.

rot. speedMULT

kMeas.

air flow

(From bleacher)

NO2

+ H2O

Compressor

K2

Shaft 1

905 Aug 2018. PEF3006 Process Control. USN.

LabVIEW programming for measurement, control and

simulation applications

1005 Aug 2018. PEF3006 Process Control. USN.

MATLAB programming

for control system simulation and analysis

1105 Aug 2018. PEF3006 Process Control. USN.

K-Spice simulation of industrial plants

1205 Aug 2018. PEF3006 Process Control. USN.

Labs: Implementing a simulator and temperature control

system of a laboratory-scale air heater

1305 Aug 2018. PEF3006 Process Control. USN.

Theory about control systems:

• Differential equations

• State-space models

• Transfer functions

• Dynamics

• Stability

• Simulation