14
ARCTIC 1 Absorption Refrigeration Cycle Turbine Inlet Conditioning Luke Buntz ARCTIC Engineer Kiewit Power Engineers Co.
ARCTIC
1
Absorption
Refrigeration
Cycle
Turbine
Inlet
Conditioning
Luke Buntz
ARCTIC Engineer
Kiewit Power Engineers Co.
ARCTIC
ARCTIC Overview
2
ARCTIC
The Problem
3
Why chill? • Increased fuel efficiency (fewer emissions)
• Power production capability and turbine efficiency increase as inlet temperature decreases
• Electricity demand is highest on the hottest days, but as ambient temperature increases air becomes less dense, therefore less power can be produced
Power is also the most valuable at these times so recovering power lost due to high ambient provides a significant Return on Investment
• Aero-derivatives: • Anti-ice systems typically heat air 10 degrees F above ambient temperature, however power capability decreases as temperature decreases below the “sweet spot” so additional heating enables higher power output • At part load, heating of the inlet air improves heat rate and emissions
• Frames: • Anti-icing is typically accomplished by using bleed air from the compressor. This results in a two-fold power reduction:
1. As inlet temperature increases, power production capability decreases
2. Bleed heat robs valuable compressed air from the combustor (ARCTIC eliminates this need)
Why heat? • Anti-icing is required in icing conditions to prevent damage to turbine blades
LM6000 PC-SPRINT
25
30
35
40
45
50
55
-40 -20 0 20 40 60 80 100 120
Gen
era
tor
Ou
tpu
t (M
W)
Ambient Temperature (°F)
80°F Maximum Wet Bulb Temperature
Sea Level
ARCTIC
25
30
35
40
45
50
55
-40 -20 0 20 40 60 80 100 120
Gen
era
tor
Ou
tpu
t (M
W)
Ambient Temperature (°F)
The Solution
4
Why ARCTIC? Operational Flexibility:
• Fast Start Capability: • On Aero units ARCTIC can be fully chilling or fully heating within 10 minutes of turbine fire
• Dispatch order: • By optimizing the heat rate at the desired power level, plant can be dispatched sooner when preference is given to heat rate
• Peaking profile: • Summer – Chill to enable maximum power • Winter – Heat (beyond anti-icing) to enable maximum power
• Load following: • Varies inlet air temperature to optimize output and heat rate, regardless of ambient temperature • Can enable maximum turndown to maintain a lb/hr emissions limitation • Ability to improve heat rate/emissions at part load conditions
• Base load: • Constant, maximum power across broad ambient temp range
• Dry Low Emissions: • Reduced fuel mapping (constant inlet temperature)
• Emissions reduction (“Green” Plants) • For same NET power production as unit with mechanical chiller, less lb of NOx and CO2 produced • For same emissions as unit with mechanical chiller, more NET power available
Heat Chill
LM6000 PC-SPRINT
ARCTIC
G
CONDENSER
HP
PUMPS
HRVGTIAC
COILS
AIR
STACK
WATER-COOLED ARCTICTM PROCESS
FUEL
COMBUSTION
TURBINE
2012-06-25
HEATING
VALVE
TCV
LETDOWN
COOLING
WATER
AMMONIA
RCVR
SPRAY
RCVR
EXHAUST
ARCTIC SKID
EVAPORATOR
Abbreviations:
TIAC – Turbine Inlet Air Conditioning
TCV – Temperature Control Valve
HRVG – Heat Recovery Vapor
Generator
REFRIGERANT
VALVERECTIFIER
How Does ARCTIC Work?
5
1. Ammonia-water solution is vaporized in the HRVG
2. The rectifier separates vapor ammonia out the top and liquid water to the bottom
3. The condenser turns the vapor ammonia to liquid
4. The liquid ammonia gathers in the ammonia receiver
5. The high pressure liquid ammonia is expanded in the TCV
6. The ammonia is evaporated, chilling the water-glycol mixture
7. The water-glycol mixture passes through the TIAC coils, chilling the inlet air
8. The vapor ammonia is recombined with the water from the rectifier
9. The ammonia-water solution is pumped back into the HRVG
10. The cycle repeats
1
2
3
4 8
9
10
6
5
7
ARCTIC
6
Reuses waste product (exhaust energy)
For same NET power as mechanical chiller, less lb of NOx and CO2
Ammonia is naturally occurring, readily available, and inexpensive
Ammonia is environmentally friendly: Ozone Depletion Potential (ODP) = zero
R-134a = 0
R-123 = 0.02
Global Warming Potential (GWP) = zero R-134a = 1300
R-123 = 90
Better heat rate = more efficient use of fuel
Water recovery from inlet coil condensate
ARCTIC
Mode Transition
7
0
10
20
30
40
50
60
70
Tim
e5
:55
:15
6:0
5:4
56
:16
:15
6:2
6:4
56
:37
:15
6:4
7:4
56
:58
:15
7:0
8:4
57
:19
:15
7:2
9:4
57
:40
:15
7:5
0:4
58
:01
:15
8:1
1:4
58
:22
:15
8:3
2:4
58
:43
:15
8:5
3:4
59
:04
:15
9:1
4:4
59
:25
:15
9:3
5:4
59
:46
:15
9:5
6:4
51
0:0
7:1
51
0:1
7:4
51
0:5
0:1
91
1:0
0:4
91
1:1
1:1
91
1:2
1:4
91
1:3
2:1
91
1:4
2:4
91
1:5
3:1
91
2:0
3:4
91
2:1
4:1
91
2:2
4:4
91
2:3
5:1
91
2:4
5:4
91
2:5
6:1
91
3:0
6:4
91
3:1
7:1
91
3:2
7:4
91
3:3
8:1
91
3:4
8:4
91
3:5
9:1
91
4:0
9:4
91
4:2
0:1
91
4:3
0:4
91
4:4
1:1
91
4:5
1:4
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LPC Inlet Air (°F)
Ambient Air (°F)
HEATING
CHILLING TRANSITION
Morning Ambient Temperature: 34°F
Afternoon Ambient Temperature: 64°F
Although the ambient temperature increased
30°F, compressor inlet temperature only
varied 6°F
Skid changes modes based on ambient
temperature
Hands-off, automated transition
Only system available that performs
both inlet conditioning functions
Am
bie
nt
Te
mp
era
ture
(°F
)
ARCTIC
ARCTIC Skid – 2000 Ton Unit
8
• Skid mounted PLC/MCC • Closed-loop • Redundant pumps • 40’ long x 14’ wide • No large components or compressors (eliminating 4160V switchgear) • Low maintenance/operation costs
Rectifier
HP Pumps
LP Pumps
PLC/MCC Panel
ARCTIC
Simple Cycle Units
9
ARCTIC
Simple Cycle – ARCTIC Output
10
75
80
85
90
95
100
105
110
115
120
75
80
85
90
95
100
105
110
115
120
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Pe
rce
nt
of
Rat
ed
Ou
tpu
t (%
)
Ambient Temperature (°F)
7FA.04 Base LM6000 Base SGT6 5000F(4)
7FA.04 ARCTIC LM6000 ARCTIC SGT6 5000F(4) ARCTIC
80°F Maximum Wet Bulb Temperature Sea Level
ARCTIC
Simple Cycle – ARCTIC Heat Rate
11
95
96
97
98
99
100
101
102
103
104
105
106
95
96
97
98
99
100
101
102
103
104
105
106
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Pe
rce
nt
of
Rat
ed
He
at R
ate
(%
)
Ambient Temperature (°F)
7FA.04 Base LM6000 Base SGT6 5000F(4)
7FA.04 ARCTIC LM6000 ARCTIC SGT6 5000F(4) ARCTIC
80°F Maximum Wet Bulb Temperature Sea Level
ARCTIC
GE Frame Simple Cycle Summary
12
Revision:
• Based on a 100°F day with 35% Relative Humidity
• Mechanical Chiller parasitic load is based on 1.6 kW/ton
• ARCTIC parasitic load is based on 0.11 kW/ton
Worst
Better
Best BaseEvaporative
Cooling
Mechanical
ChillerARCTIC
Output Gain 158,107 8.7% 14.8% 21.1%
Heat Rate Reduction 10,310 -0.1% 3.2% -2.2%
Efficiency Improvement 33.1% 0.0% -1.0% 0.8%
Output Gain 192,594 7.9% 10.6% 16.1%
Heat Rate Reduction 10,085 -1.2% 2.1% -2.8%
Efficiency Improvement 33.8% 0.5% -0.8% 1.1%
Output Gain 75,360 8.3% 15.0% 22.6%
Heat Rate Reduction 11,812 -1.8% 1.8% -4.5%
Efficiency Improvement 28.9% 0.6% -0.6% 1.5%
7FA.05
7EA
7FA.04 *
*
*
* Heat rates based on fuel HHV
ARCTIC
GE Aero Simple Cycle Summary
13
Revision:
BaseEvaporative
Cooling
Mechanical
ChillerARCTIC
Output Gain 37,606 20.3% 28.1% 35.6%
Heat Rate Reduction 9,868 -4.6% -0.2% -5.7%
Efficiency Improvement 34.6% 1.8% 0.1% 2.3%
Output Gain 43,887 13.8% 24.7% 32.1%
Heat Rate Reduction 9,793 -2.7% 2.5% -3.2%
Efficiency Improvement 34.9% 1.1% -0.9% 1.3%
Output Gain 41,653 7.7% 17.3% 25.1%
Heat Rate Reduction 9,713 -1.9% 1.8% -4.5%
Efficiency Improvement 35.1% 0.7% -0.7% 1.8%
Output Gain 93,917 4.0% 8.4% 10.8%
Heat Rate Reduction 9,011 -1.1% -0.7% -2.8%
Efficiency Improvement 37.9% 0.5% 0.3% 1.2%
Output Gain 83,912 4.4% 11.2% 16.8%
Heat Rate Reduction 8,997 -1.3% 0.4% -4.4%
Efficiency Improvement 37.9% 0.6% -0.2% 2.0%
Output Gain 26,006 13.7% 22.1% 30.2%
Heat Rate Reduction 10,373 -3.1% 0.6% -5.7%
Efficiency Improvement 32.9% 1.1% -0.2% 2.2%
LM25
+G4
LM6
PCS
LM6
PGS
LM6
PHS
LMS
PA
LMS
PB
Worst
Better
Best
* Heat rates based on fuel HHV
*
*
*
*
*
*
ARCTIC
ARCTIC Contacts
14
These values are based on power production at the generator terminals minus the parasitic loads of the inlet conditioning and some SCR tempering loads.
Chris Mieckowski
ARCTIC Product Line Manager
913.928.7304
Luke Buntz
ARCTIC Engineer
913.689.3931
