hybrid instrument air dryer
TRANSCRIPT
An Innovative Solution to Save Energy, Improve Reliability and Reduce Maintenance Cost
Abdulmajeed Alshaye, Saudi Aramco
12/06/2017
Hybrid Instrument Air Dryer
© 2017, Saudi Aramco
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Saudi Aramco: Company General Use
• Objective
• Introduction to IA (instrument air)
• Challenges with the IA system
• High air temperature effect on desiccant dryer
• Hybrid dryer configuration
• Summary
Contents
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Saudi Aramco: Company General Use
To share with you a new concept of compressed air drying:
• Use the minimum amount of energy to operate
• Ensure a constant, low and reliable outlet dew point
• Safe failure mode
• Low maintenance and operation cost
Objective
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Saudi Aramco: Company General Use
Introduction to IA
Unit A
Unit B
Unit C
Unit D
Unit E
Compressor After cooler Separator Wet receiver Pre-filter Dryer
After filter
Dew point Dry receiver Dry receiver
PA
IA
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Saudi Aramco: Company General Use
Introduction to IA
Heat of compression; 80%
[CATEGORY NAME] [VALUE]
[CATEGORY NAME] [VALUE]
[CATEGORY NAME]
10%
1 hp (Final use) 10 hp (Motor) 30 hp (Power plant)
𝜂= 𝐸𝐸𝐸𝐸𝐸𝐸 𝑠𝑠𝑠𝐸𝐸𝑠 𝑖𝐸 𝑐𝑠𝑐𝑐𝐸𝐸𝑠𝑠𝐸𝑠 𝑎𝑖𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑖𝐸𝑐𝑖𝑠 𝑖𝐸 𝑠ℎ𝐸 𝑐𝑠𝑠𝑠𝐸
Q. How much compressed air cost us?
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Saudi Aramco: Company General Use
Challenges with IA
• High IA losses (up to 50%)
• High outlet dew point (+70° F)
• Header pressure fluctuation (15%)
• Frequent dryer valves failures
• Condensate drainage
• Portable compressor rental
• Plant safety
• Process interruption
• High maintenance cost
• Less redundancy
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Saudi Aramco: Company General Use
0
2000
4000
6000
8000
10000
12000
14000
Flow
rate
, scf
m
Total production
Total consumption (IA+PA)
Challenges with IA (high losses)
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Saudi Aramco: Company General Use
0
10
20
30
40
50
60
70
۲:۰۰ ۲:۱۰ ۲:۲۰ ۲:۳۰ ۲:٤۰ ۲:٥۰ ۳:۰۰ ۳:۱۰ ۳:۲۰ ۳:۳۰ ۳:٤۰ ۳:٥۰ ٤:۰۰
Dew
poi
nt,
°F
Dew point trend on May 26, 2016, midnight
Challenges with IA (dew point)
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Saudi Aramco: Company General Use
Challenges with IA (pressure swinging)
90
95
100
105
110
۱۳:۰۰ ۱۳:۰٤ ۱۳:۰۸ ۱۳:۱۲ ۱۳:۱۷ ۱۳:۲۱ ۱۳:۲٥ ۱۳:۲۹
Hea
der
pres
sure
(PS
I)
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Saudi Aramco: Company General Use
Challenges with IA (filters damage)
Dryer pre-filter Dryer after filter Dryer after filter Plant instruments
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Saudi Aramco: Company General Use
Challenges with IA (condensate drain)
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Saudi Aramco: Company General Use
High air temperature effect (dryer Inlet)
1. High energy consumption
2. Dryer valve malfunctioning
3. Short desiccant life
4. Filters damage
5. Not meeting IA quality requirement (ISO 8573)
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Saudi Aramco: Company General Use
High air temperature effect (dryer Inlet)
90
100
110
120
130
140
150Te
mpe
ratu
re, °
F
Example for dryer inlet temperature
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27/10/2014 Copyright note text (8pt)
High air temperature effect (dryer Inlet)
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47.1
32.2
24.6
19.61
14.7 11.4
8.4 6.4
4.5 3.4 2.3 1.6 0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
۱٥٦ ۱٤۰ ۱۳۰ ۱۲۰ ۱۱۰ ۱۰۰ ۹۰ ۸۰ ۷۰ ٦۰ ٥۰ ٤۰
Wat
er c
onte
nt g
al/h
r
Air temperature in Degree F
Air water content for 5,000 scfm at 132 PSIA
High air temperature effect (Dryer Inlet)
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Saudi Aramco: Company General Use
Hybrid dryer configuration
• This innovative system is relying on two concepts
1. Precooling the compressed air before the desiccant dryer
2. Utilize a external purge heated type desiccant dryer
Working In
Series
Complement &
Independent
Cooling +
Adsorption
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Saudi Aramco: Company General Use
Hybrid dryer configuration
Chilled water
5,000 scfm, 125 psi of compressed air To PA
To IA 250°F 70°F 140°F
250° F
[VALUE]° F
[VALUE]°F 90
47 G/h [VALUE] G/h
[VALUE] G/h [VALUE] G/h 0
50
100
150
200
250
300
Heated desiccant dryer Cyclone 1st aftercooler 2st aftercooler
Air
tem
p. /
wat
er c
onte
nt
Plant cooling water Air compressor
PDP:5°F
1 2 3
86%
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Saudi Aramco: Company General Use
Traditional dryer configuration
• Heatless dryer design
• Purge losses > 20%
• Switching time: 5 minutes
• Valves are prone to failures
• Using single aftercooler
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Saudi Aramco: Company General Use
Hybrid dryer configuration
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Saudi Aramco: Company General Use
• Adsorption dryer and refrigeration dryer
• High capital cost
• High pressure drop
• Low flexibility
Hybrid dryer configuration
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Saudi Aramco: Company General Use
Hybrid dryer configuration (chiller + dryer)
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Saudi Aramco: Company General Use
Hybrid dryer configuration (aftercooler)
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Saudi Aramco: Company General Use
Hybrid dryer configuration (benefits)
1. Reduce the compressed air losses in the utility to less than 2% (now 30-50%).
2. Increase the desiccant dryer switching time from 5 minutes to 48 hours.
3. Significantly improve the quality of the delivered instrument air dew point.
4. Provide dry air for plant air application.
5. Reduce the maintenance cost.
6. Increase instrumentation reliability.
7. Minimize process interruption.
8. Produce pure water as a byproduct.
9. Reduce instrument air pressure fluctuation.
10. Condense the majority of harmful gases in the air.
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Saudi Aramco: Company General Use
Summary
• Compressed air is inherently energy inefficient
• Hybrid dryer design is well suited for hot and humid locations
• Benefits: Energy, Safety, Reliability, Environment, Asset integrity
Availability, Maintenance cost and Compliance
• Flexible operation
• Existing plants or new projects
• Potential energy saving (kingdom): 150 Mw
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Saudi Aramco: Company General Use
Thank you