MEE INDUSTRIES INC, GAS TURBINE DIVISION IMPROVING GAS TURBINE PERFORMANCE WITH WATER FOGGING SYSTEMS ASME/API/ISO Gas Lift Workshop February 15, 2006 Dara Masani MEE INDUSTRIES INC, GAS TURBINE DIVISION 204 West Pomona Ave, Monrovia, CA 91016 www.meefog.com
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MEE INDUSTRIES INC, GAS TURBINE DIVISION
IMPROVING GAS TURBINE PERFORMANCE WITH WATER FOGGING SYSTEMS
ASME/API/ISO Gas Lift Workshop
February 15, 2006
Dara Masani
MEE INDUSTRIES INC, GAS TURBINE DIVISION
204 West Pomona Ave, Monrovia, CA 91016
www.meefog.com
MEE INDUSTRIES INC, GAS TURBINE DIVISION
• Introduction
Presentation outlinePresentation outline
MEE Industries, Inc. 204 West Pomona Avenue, Monrovia, California 91016, Tel. (800) 732-5364, Fax. (626) 359-4660, URL: www.meefog.com
Gas turbine inlet air fogging principlesGas turbine inlet air fogging principles
Psychrometrics of Inlet Fogging
Effects of Gas Turbine Inlet Configuration
Practical ConsiderationsPractical ConsiderationsExperimental Results and AnalysisExperimental Results and Analysis
ConclusionConclusion
MEE INDUSTRIES INC, GAS TURBINE DIVISION
• Increased output
• Improved heat rate
• NOx reduction
• Longer compressor wash intervals
• Easy to specify and install
• Simple to service and maintain
• Field tested, proven technology
• Rapid project execution
• Excellent return on investment
• Increased process production
Benefits of MeeFog
MEE INDUSTRIES INC, GAS TURBINE DIVISION
T
H
DrainSilencer
Drain
Drain
Fog Nozzle Manifolds
Fog Pump Skid
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Inlet Air Fogging - Basic Concept
Air FilterHousing
Gas Turbine
Temperature
Humidity
Drain
Fog Pump Skid
Fog Nozzle Manifolds Fog evaporates
& cools the air
De-min water
Cooler inlet air reduces compressor sp.work increased output.
Compressor moves a constant volume of air ...
Cooler air is denser. More mass = more output.
Inlet Fogging Power Boost
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Typical MeeFog Installation
Oversized Inlet Water Filter (0.35 micron)
Fog Pump Skid with 5 Pumps
High Pressure Feed Lines (stainless steel tube)
Motor Control Center with Computer and Operator
Interface Panel and Weather Station
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Fog Nozzle Manifolds
Mee Fog nozzle manifolds are designed to avoid air-flow
induced vibration using proprietary software.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Fog Nozzle Manifolds
Nozzle Manifolds are installed in one cross sectional plane in the inlet duct.
Nuts and fittings tack-welded to avoid FOD.
High-pressure tube system meets operating pressure requirements
of ANSI B31.1 and B31.3
Feed lines from pump skid allow for staged
fog water output.
Stainless steel strut supports, welded to duct wall. Tube
clamps with vibration absorbing cushions.
Fog nozzles safety wired to manifolds.
Tube fittings: 316 stainless steel
compression type.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Pump Components
Pressure Regulator
Pulsation Dampener
High Pressure
Gage
Ceramic Plunger Pump
Stainless Steel Pump Head
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Pump Skid
Pressure Regulator
Pulsation Dampener
Inlet Solenoid Valve
Inlet Pressure Switch Discharge Pressure Switch
High Pressure Gauge
Stainless Steel Pump Head
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Inlet Filter Components
Flow Sensor
Inlet water port
Inlet Filter Gauge
Wing nuts
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Control Systems
PLC computes cooling potential, controls fog
cooling stages, manages pump rotation, etc.
Weather sensors measure ambient temperature and relative humidity.
Flow meter displays total water flow.
FEATURES AVAILABLE
•PART LOAD CONTROL
• Flow related adjustments
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Installation Photographs
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Effect of CIT on Power, Flow, and Heat Rate
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Mee Fog Evaporative Cooling
Gas Turbine
Drain
Fog Pump Skid
De-min water
Almost no fog droplets enter the compressor
The Mee Fog Advantage ...
• Easy to retrofit (1 to 2 days downtime)
• Very small pressure drop
• Adjustable cooling
• 100% effective evaporative cooling
Temperature
Humidity
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Fog Intercooling
T
H
Drain
De-min water
Un-evaporated fog enters compressor & reduces work of compression
Power Boost from Fog Intercooling is about 5-10% for every 1% (weight) of air mass flow
water injected.
Drain
Control System Injects more fog than will
evaporate in the duct
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Typical Daily Weather
Rel
ativ
e H
umid
ity
65°F
70°F
75°F
80°F
85°F
Relative Humidity
Dew Point Temperature
Evaporative Cooling Potential 16° F (9° C)
Dry Bulb Temperature
90°F
95°F
40%
50%
60%
70%
80%
90%
30%8:00 10:00 12:00 14:00 16:00 18:00
Wet Bulb Temp
35°C
30°C
25°C
20°C
MEE INDUSTRIES INC, GAS TURBINE DIVISION
W B and D B A ver ag e C o r r e la t io ns
0
5
1 0
1 5
20
25
30
35
40
0 5 1 0 1 5 20 25 30 35
D r y B ul b T e mp, D e g C
Correlation of WB and DB temperatures-averaged dataDaily variation of dry bulb and wet bulb temperatures
20
25
30
35
40
0 5 10 15 20 25
Time of the day (hours)
Tem
pera
ture
(ºC
)
25
35
45
55
65
75
Rel
ativ
e H
umid
ity (%
)
DB (ºC) WB (ºC) RH (%)
Required data: Coincident dry bulb and wet bulb temperatures
Common errors include:
1. Providing average data instead of coincident data
2. Using the max relative humidity and the max dry bulb instead of coincident data
Usable data Unusable data
MEE INDUSTRIES INC, GAS TURBINE DIVISION
15
20
25
30
35
40
45
50
0 24 48 72 96 120 144 168Time (Hours)
DB
T, W
BT
(ºC
)
10
20
30
40
50
60
70
80
Rel
ativ
e H
umid
ity (%
)
DB (ºC) WB (ºC) RHData taken in Riyadh, KSA between 10 and 17 of July 1991
Max of 23 ºC of cooling
Evaporative cooling area
Min of 5 ºC of cooling
MEE INDUSTRIES INC, GAS TURBINE DIVISION
ANALYSIS OF CLIMATIC CONDITIONS IN THE MIDDLE EAST- DUBAI
MEE INDUSTRIES INC, GAS TURBINE DIVISIONEquivalent Cooling Degree Hours (ECDH, °C.hr) by wet bulb depression groupings. Minimum wet bulb temperature at 12.8°C.
SA, Uanbu Al Bahr 3138 2984 4214 5303 5772 5646 5539 6490 5222 4542 4205 3576 56631
Available Yearly and Monthly ECDH
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Important Fog System Design Considerations
Gas TurbineT
H
Drain
Fog Pump Skid
Nozzles & Manifolds• Small droplets• Good mixing• FOD avoidance• Residence time
Windows and Lights• Visual monitoring
Drain
Small droplets
•Faster evaporation = lower inlet temp.
•Less fallout = less pooling
•Droplets less than 10-20 microns do not
contact compressor blades
Drains, Dams & Gutters
•Remove pooled water
•Avoid un-atomized water entering compressor
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Drain Locations
Drain
Drain
All inlet fog systems require duct drains. Water flow is much less when droplets are small.
Floor drain with water dam near
Nozzle Manifolds.
Floor drain with water dam before
transition Wall gutter (may not be required with perforated
duct walls).
Floor drain with baffle Plates above.
Channel to keep water from being suctioned
over bell-mouth
MEE INDUSTRIES INC, GAS TURBINE DIVISIONMEE INDUSTRIES INC, GAS TURBINE DIVISION
Nozzle Manifold Positions
The position of the nozzles manifold in the duct should be chosen with care. In general there are three positions in the gas turbine duct where nozzle manifolds could be installed.
• Close to the inlet filter housing where the airflow velocity isaround 2.5 m/s (500 fpm), this position is commonly used for evaporative fogging applications, typical residence time of 1 second.
• After the silencer where the velocity is around 12.7 m/s (2500 fpm). This position is used for evaporative fogging and for combined overspray fogging.
• In the duct close to the axial compressor inlet, which is the typical overspray installation, where the residence time will be of the order of 0.2 seconds. The velocity here would also be close to 12.7 m/s (2500 fpm)
Total annual maintenance requirement, less than 30 hours per turbine per year.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Winterization and Draining
Open inlet drain valve
Drain all water from high pressure feedlines.
Loosen nuts to let air into the filter canister.
Open the drain valve at each pump
Blow out lines with compressed air if gravity draining if not sufficient. Close all valves after draining to keep dust and dirt out of the system.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
MEE Industries, Inc. 204 West Pomona Avenue, Monrovia, California 91016, Tel. (800) 732-5364, Fax. (626) 359-4660, URL: www.meefog.com
POWER BOOST FOR OVERSPRAY
0
5
10
15
20
25
30
35
0 0.3 0.6 0.9 1.2 1.5
% of water injected in the flow
Powe
r Boo
st (%
)
S ol Mars 2s ABB GT 8C W501 DJGE 7121 EA KWU V94.3A EGT Typhon
Saturation 0.5% Overspray 1% Overspray
DBT= 37.8°C (100°F)WBT= 26.1°C (79°F)
Overspray fogging is derived by the deliberate introduction of fog into the compressor.
Experimental investigation of overspray on 115 MW Hitachi Fr 9E by Utamura (1999) – 10% gain in power with 1% overspray.
Several existing gas turbines utilize overspray as a means for augmenting power
Most machines operate with an overspray level not exceeding 2% of the air mass flow but the limiting number is machine specific.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Swirl Jet and Impaction Pin Nozzles
MEE INDUSTRIES INC, GAS TURBINE DIVISION
MeeFog Nozzles
Internal filter, 40 micron particle
size, replaceable
Type 316 stainless steel
Orifice 0.006 inch diameter (150 microns)
Impaction Pin
O-Ring seal
Nozzle Adapter, soldered and riveted to tube - fail safe
TIG Welding OptionStainless steel tube
(ASTM A269)
Safety wire protects turbine against FOD.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
MEE Industries, Inc. 204 West Pomona Avenue, Monrovia, California 91016, Tel. (800) 732-5364, Fax. (626) 359-4660, URL: www.meefog.com
Fog DropletsFog Droplets
Water Sheet Water Sheet FormationFormation
NozzleNozzle
Impaction-Pin
UNDERSTANDING BEHAVIOR AND DYNAMICS OF FOG DROPLETS
There are several interacting factors that define the success andefficiency of the evaporation process, such as:
Droplet mean size
Droplet size distribution
Patterns and penetration of droplets in the plume for a given cone angle
Properties of water
Geometries of nozzle (spray angle)
Pressure applied on the liquid and the air flow rate
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Nozzle Fog Dynamics in an Airstream
Large droplets react slowly to air flow and
tend to stay at the outer edge of the plume.
Smaller Droplets are pushed towards the center of plume.
This results in less coalescence but coalescence still occurs.
Mee Fog Nozzles: Collision and coalescence ends at about 7 inches (due to lower droplet
concentration and smaller droplets).
For pressure type nozzles, most of the water mass
flow is found at the edge of the plume
Close to nozzle; droplet velocity high, shattering
and breakup occur.
Collisions and coalescence continues past 12 inches for nozzles producing larger droplets
and/or having higher flow rates.
1” 2” 3” 4” 5” 6” 7” 8” 9” 10” 11” 12”
High velocity air results in smaller droplets but coalescence (agglomeration) is still an important factor
2500 ft/min. air velocity
MEE INDUSTRIES INC, GAS TURBINE DIVISIONMEE INDUSTRIES INC, GAS TURBINE DIVISION
Droplet Size Measurement Location
@2500 fpm, in the center of the plume
D32=4.8 microns
Dv90=11.5 microns
Average @2500 fpm
D32=8.5 microns
Dv90=18 microns
Average @2500 fpm in the center of the plume
D32=7.1 micronsDv90=14.7 microns
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Comparing Droplet Sizes
60 micron• 27 times more mass and force of
impact• 66% less surface area per unit volume• 9 times faster fall rate• 9 times times potential for fallout
from centrifuging.
Droplets are spheres. Thinking about them only in terms of diametercan be misleading.
30 micron• 3.4 times more mass
and force of impact• 33% less surface / unit volume• 2 times faster fall rate • 2 times potential for fallout
from centrifuging.
20 micron
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Droplet Diameters
• Mass Median Diameter (MMD ) DM50- this is the diameter in microns, which divides the mass of the fog into two equal halves. Half (50%) of the total mass is made up of droplets with diameters smaller than this number and the other half (50%) of diameters higher than the number.
• DV90- is the value where 90% of the total volume of water in the fog is made up of drop with diameters smaller or equal to this value. A small value of this number indicates that a very small volume of larger droplets is produced, which minimizes any potential erosion effects on compressor components should these be carried over into the compressor.
Sauter Mean Diameter (SMD) D32- is a means of expressing the fineness of the fog in terms of the surface area produced by the spray. The SMD is the diameter of a drop having the same volume to surface area ratio as the total volume of all the drops to the total surface area of all the drops. This is a good measurement to indicate the evaporation rate of the fog droplets
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Impaction Pin Vs. Swirl Jet Nozzles
• Less defined plume edge.
• Denser, whiter looking fog.
• Plume more smoke-like.Impaction-pin nozzle at 2000 psi, 0.045 gpm. Dv90 at 10 inches = 21 microns.
Swirl-jet nozzle at 3000 psi, 0.073 gpm, Dv90 at 10 inches = 29 microns
Smaller droplets from impaction-pin nozzles are observable …
Swirl-jet nozzle, with 1.6 times higher flow rate. Larger droplet size is observable:• Defined plume edge.
• Spray less opaque.
• Plume less smoke-like.
Smaller plume, with more water flow, results in more coalescence.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Plume characteristics of impaction-pin (left) and swirl-jet type nozzles (right) at operating pressure of 137 barg (2000 psig). The smoke-like nature of the impaction-pin nozzle is evident. The
straight edge of the swirl-jet nozzle is indicative of the high momentum of the larger droplets, implying a much larger droplet size at the edges as also indicated by the graphs above
Impaction-Pin Swirl-Jet
Flow Rate 0.036 gpmFlow Rate: 0.045 gpm
-22%
MEE INDUSTRIES INC, GAS TURBINE DIVISION
MEE Industries, Inc. 204 West Pomona Avenue, Monrovia, California 91016, Tel. (800) 732-5364, Fax. (626) 359-4660, URL: www.meefog.com
EFECTS OF GAS TURBINE INLET CONFIGURATION AND NOZZLE CHARACTERISTICSNozzle Orientation and Fog Distribution
Nozzle orientation depends on:
airflow velocity
distance between nozzle manifolds
operating pressure
duct wall
roof shape constraints
duct geometry
Nozzle manifolds in operation at 138 bar operating pressure and with
airflow velocity of 5 m/s
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Co-flow position of MeeFog nozzle in wind tunnel, air flow velocity of 800 fpm
Ninety degree position of MeeFog nozzle in wind tunnel, air flow velocity of 800 fpm
Counter-flow position of MeeFog nozzle in wind tunnel, air flow velocity of 800 fpm
The fundamental factor driving the design of nozzle orientation and distribution is to obtain uniform droplet distribution in the intake duct, and to thereby ensure that the airflow is evenly cooled.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Impaction Pin Vs. Swirl Jet Nozzles
• Less defined plume edge.
• Denser, whiter looking fog.
• Plume more smoke-like.Impaction-pin nozzle at 2000 psi, 0.045 gpm. Dv90 at 10 inches = 21 microns.
Swirl-jet nozzle at 3000 psi, 0.073 gpm, Dv90 at 10 inches = 29 microns
Smaller droplets from impaction-pin nozzles are observable …
Swirl-jet nozzle, with 1.6 times higher flow rate. Larger droplet size is observable:• Defined plume edge.
• Spray less opaque.
• Plume less smoke-like.
Smaller plume, with more water flow, results in more coalescence.
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Plume characteristics of impaction-pin (left) and swirl-jet type nozzles (right) at operating pressure of 137 barg (2000 psig). The smoke-like nature of the impaction-pin nozzle is evident. The
straight edge of the swirl-jet nozzle is indicative of the high momentum of the larger droplets, implying a much larger droplet size at the edges as also indicated by the graphs above
Impaction-Pin Swirl-Jet
Flow Rate 0.036 gpmFlow Rate: 0.045 gpm
-22%
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Plume characteristics of impaction-pin (left) and swirl-jet type nozzles (right) at operating pressure of 207 barg (3000 psig). The smoke-like nature of the impaction-pin nozzle is evident. The
straight edge of the swirl-jet nozzle is indicative of the high momentum of the larger droplets, implying a much larger droplet size at the edges as also indicated by the graphs above
Impaction-Pin Swirl-Jet
Flow Rate 0.072 gpmFlow Rate: 0.055 gpm
+36%
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Impaction-Pin and Swirl-Jet Nozzles
Swirl-Jet
Impaction-Pin
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Factors Affecting Droplet Size
FACTORS AFFECTING DROPLET SIZE
• Air flow velocity during the measurement
• Position of measurement i.e., is the measurement taken at the center, or the edge
• Ambient conditions around the droplet, temperature and relative humidity
MEE INDUSTRIES INC, GAS TURBINE DIVISION
Intake Area Drop Behavior- Suctioning
B. Some water from condensation of droplets on the duct wall after the bend is suctioned around the bell mouth.
D. Pooled water can be suctioned into the compressor.
C. Large Water Droplets settle on the duct floor and form pools of water.
A. Large droplets in the air stream are drawn directly into the compressor or they impact on the inlet cone and are suctioned in.