1.2 Overview of Plant Operation
-
Upload
sreedhar-rakesh-vellanki -
Category
Documents
-
view
218 -
download
1
Transcript of 1.2 Overview of Plant Operation
1
Overview of Plant Operation
by Dr. AA
Objectives of Plant Operation
Ensuring that the plant has the capacity and flexibility to achieve a range of operating conditions safely, reliably, profitably and with good dynamic performance
2
We need to establish good operability
• Follow work system & procedure
• troubleshoot problems
• Making decision & taking effective action
Consider a Distillation System Methane as main product at the Top
3
E9
FI1
TI1 TI5
AI10
FI9
Feed
Methane Ethane (LK) Propane Butane Pentane
P 1000 kPa T 298 K
TI3
TI4
TI2
TI7
TI6
TI10
FI10
AI9
FI8 TI9
LI9
PI9
E2 E1
T1
M9
M10
E10
Process fluid
Steam
People & Environmental Protection
Equipment Protection • Product Specification • Economy
Workshop Out of Control !
Handouts will be given in classroom
4
Challenges in Modern Plant
More stringent product specifications
Tighter Constraints due to low over-design margin
More interactions due after removing intermediate storage
More complex plant structure due to process integration
5
More Stringent Quality Requirement
-1s 2s m -3s
0.135 % 0.135 %
+1s +2s +3s
99.73 %
m ± 3 s
Traditionally three-
sigma is acceptable,
now, the industry is on
six-sigma
-1s 2s m -3s +1s +2s +3s
99.9999998%
m ± 6 s
-6s +6s
6
Reduced Variability Product
7
Goal: Maximize conversion of feed ethane but do not exceed 864 oC
Which operation, A or B, is better?
Explain why.
864 C Temp.
Co
nve
rsio
n
0
0.1
0.2
0.3
0.4
0.5
0.6
842 846 850 854 858 862
Temperature
freq
uen
cy
0
0.05
0.1
0.15
0.2
0.25
842 846 850 854 858 862
Temperature (C)
freq
uen
cy
B
A
FC
TC
Fuel
Ethane
Feed
Flue gas
AC
Air
8
Improving Efficiency by Operating Near Constraints
Which operation, A or B, is better?
Explain why.
B A
0
0.1
0.2
0.3
0.4
0.5
0.25 1.25 2.25 3.25 4.25 5.25
O2 mole %
fre
quency
80
82
84
86
88
Effic
iency %
Frequency
Efficiency
0
0.05
0.1
0.15
0.2
0.25
0.25 1.25 2.25 3.25 4.25 5.25
O2 mole %
frequency
80
82
84
86
88
Effic
iency %
Frequency
Efficiency
FC
TC
Fuel
Ethane
Feed
Flue gas
AC
Air
9
Reduced Variability in Performance
10
Process Interaction
E9
FI1
TI1 TI5
AI10
FI9
Feed
Methane Ethane (LK) Propane Butane Pentane
P 1000 kPa T 298 K
TI3
TI4
TI2
TI7
TI6
TI10
FI10
AI9
FI8 TI9
LI9
PI9
E2 E1
T1
M9
M10
E10
Process fluid
Steam
Discuss Process Interactions issues in this plant
• Set goals and design specifications
• Select process technology
• Define process structure (sequence)
• Simulate the flowsheet
• Design equipment
Construct and start up
Often performed for
one operating point
Operate the plant over a range
of conditions, many operating
points and transitions between
them
Inconsistency!
Between Design & Operation
11
The design procedure should ensure that the plant
is operable, that it functions “well”. This requires a
specification that addresses a range of conditions,
for example:
• Feed compositions and rates
• Product qualities
• Equipment capacities and availabilities
• Environment (summer, winter)
• Major disturbances
Process Design With Operability
12
What do the following words have in common?
Music Love
Operability Happiness
Class Workshop
13
I need to regulate the flow,
but how complex should the
equipment be?
Does the need for operability
affect this decision?
From the simplest to
most complex process,
we must think about
operability!
14
15
Conclusion I’ll think about it !!