HRSG Overview.pdf
Transcript of HRSG Overview.pdf
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HRSG Overview
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HRSG Overview
HRSG Systems - An Overview
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HRSG Overview
Mechanical & Design Benefits
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HRSG Overview
High velocity and highly turbulent region
30 / 60 Inlet Duct Configuration
Cold Casing design internally insulated and lined
12/16 gauge stainless steel inner liner (2.67mm / 1.52mm)
12.7mm (1/2) studs on 279.4mm (11) centers
6mm carbon steel (SA-36) outer casing
Shipped in flat panels limited in size by shipping clearance.
Section 1 - HRSG Inlet Transition Duct
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HRSG Overview
All welded header design to enhance reliability and lower life cycle costs
Fully drainable & ventable to improve cycling capability
Fully Top supported pressure parts allows for unrestrained thermal growth
Section 2 Superheaters/Reheaters
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HRSG Overview
Section 2 Superheaters/Reheaters
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HRSG Overview
Staggered or Inline Tube Pitch
38.1mm (1 1/2), 44.5 mm (1 3/4") or 50.8mm (2) O.D. Tubing
88.9 mm x 88.9 mm (3.5x3.5) to 101.6 mm x 101.6 mm (4x4) tube spacing
Serrated or solid finning
Section 2 Superheaters/Reheaters
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HRSG Overview
3rd Party Engineered products, integrated into the HRSG system.
Locations in the HRSG Inter-staged firing or up-front firing
Variety of fuels that can be fired:
natural gas, No. 2 oil, or heavy oil firing
Horizontal/Vertical runner (element), side firing. Available with continuous/intermittent pilots,
element isolation and a range of turndown.
Burners, Fuel Skid, Cooling Air, BMS
Section 3 Duct/Grid Burner System
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HRSG Overview
Section 3 Duct/Grid Burner System
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HRSG Overview
Cold casing design, internal insulation with external stiffeners.
Internal Construction Options Moderate firing < 730 C
ceramic fiber insulation with stainless steel internal liner
High firing > 730 C
Y-Bloc ceramic insulation module rated to 1090C without internal liner
Shipped in flat panels limited in size by shipping clearance.
Section 4 - Burner Outlet Transition Duct
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HRSG Overview
CO & SCR Systems 3rd Party Engineered products,
integrated into the HRSG system.
Modularized construction to reduce overall field installation labor
Configured in the system to permit access for maintenance and catalyst replacement without removal of HRSG piping/structures.
Section 5 Emission Control Systems
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HRSG Overview
Section 5 Emission Control Systems
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HRSG Overview
Drum shell/heads material in accordance with boiler codes
(SA-516 Gr 70 or SA-299)
Hold retention duration determined by specification requirements
Hinged manway access305mm x 406mm minimum
Two-stage steam purification system with primary separators and secondary dryers.
Shipped as completed assembly including:
Nozzle connections, steam purification equipment and internal piping, drum saddles
Section 6 Steam Drums
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HRSG Overview
Vortexes Used for Steam Separation and Circulation
Alternative : perforated sheets
Chevrons Used for Steam Purification
Alternative : mesh dryer
Section 6 Steam Drums
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HRSG Overview
All welded design Fully top supported pressure parts
pipe support (drum support) for HP
rod and clevis supports for IP and LP
Staggered or Inline tube pitch 38.1mm (1 1/2), 44.5 mm (1 3/4") or 50.8mm
(2) O.D. Tubing
88.9 mm x 88.9 mm (3.5x3.5) to 101.6 mm x 101.6 mm (4x4) tube spacing
Serrated or solid finning T-11, P-11 safe ends in upper bend areas in
the LP evaporator to minimize flow assisted corrosion (FAC) damage
Section 7 HP, IP, LP Evaporators
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HRSG Overview
All welded header design
Fully drainable and ventable
Fully top supported pressure parts
Staggered or Inline tube pitch
38.1 mm (1-1/2) O.D. tubing
88.9 mm x 88.9 mm (3.5x3.5) tube spacing
Serrated or solid finning
Section 8 - Economizers
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HRSG Overview
Similar to other system Economizers in design approach except: Multiple tube and finning material options
based on considerations of
oxygen pitting on the tube inside surfaces
gas side fouling on the tube outside surfaces
acid dewpoint considerations due to sulfur in the fuels
Splitted bottom header for first pass utilized in area of water entry to avoid damage due to thermal shock
Can be fabricated from Austinetic or Ferritic tube material depending on requirements.
Section 9 - Feedwater Heater
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HRSG Overview
Single or two-stage purification system can be provided depending on facility requirements for steam
Sizing can be adjusted based on specific needs of the facility.
Section 10 - LP Steam Drum
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HRSG Overview
Horizontal or vertical configurations
Tray type or Spray and Tray type designs
Connected directly to LP steam drum with no intervening valves.
Floating Pressure operation.
Section 11 - Integral Deaerator
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HRSG Overview
Section 12 - Stack Assembly
Free standing, single wall design Designed to prevailing site
conditions based on civil/structural codes and ANSI STS-1.
Isolation dampers and silencers can be included as necessary in the stack assembly.
Supplied in a variety of arrangements based on shipping limitations and field construction needs.
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HRSG Overview
Installed in stack above breeching to reduce heat loss.
Counterweigted to open + interlocked into DCS for safety.
Shipped in match marked pieces after shop pre-assembly.
Section 12 - Stack Dampers
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HRSG Overview
Stair access on one side, ladder access on opposite side.
Open bar type grating with supporting steel.
2 or 3 rail handrail system. Provided for access to equipment in
the following areas:
main operating platform, both sides
steam drum safety valve access
stack access to emission ports and stack closure damper (if required)
burner maintenance, flame observation
Fabricated in sections that can be hot dip galvanized or painted
Section 13 - Ladders and Platforms
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HRSG Overview
HRSG Packaging Options are based on evaluation of shipping access, shop location and site capability to provide the most economical package
Modular Box Design Approach (highest degree of shop assembly)
C-Section Modular Design Approach
Field Modular Design Approach
Field Platen Design Approach (lowest degree of shop assembly)
HRSG Constructability
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HRSG Overview
HRSG Constructability
Systems are provided in various configurations to meet size and/or site limitations.
OOField Platen
Field Modular
C-Section
Shop Modular
XX
OO
X
3 Wide2 Wide1 Wide
X = standard O = optional
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HRSG Overview
Modular Box Design Approach:
Highest degree of shop modularization with tube bundles shipped with the casings and supporting structures shop installed.
Due to shipping limitations this approach usually only applies to Single Wide HRSG systems.
In some instances, steam drums and interconnecting piping can be shop installed.
Requires a detailed and thorough review of shipping clearances to assure access to the site.
HRSG Constructability
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HRSG Overview
Loading of Modular Box for Transport
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HRSG Overview
Setting of Modular Box at Site
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HRSG Overview
Field Modular Design Approach
Configuration based on maximizing the tube bundle size based on shipping limitations. Heat transfer sections are prefabricated in modules (tube
bundles) with interconnecting piping installed.
Structural support steel and casing panels are shipped separtely from the modules which permits earlier site work and pre-assembly.
This approach can support either top loading or side loading of the tube bundles and can support any sequence of installation (left side first, right side first, front to rear, rear to front)
HRSG Constructability
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HRSG Overview
Field Modular Approach
Side Loading the first tube bundle in a Double Wide HRSG
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HRSG Overview
Field Modular Approach
Close up of the showing degree of shop assembly
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HRSG Overview
Field Platen Design Approach
Configuration based on very low component weights to facilitate inland transportation.
Individual tube platens consisting of finned tubes and upper/lower headers are shipped loose.
Interconnecting piping is shipped loose.
Structural support steel and casing panels are shipped separtely from the modules which permits earlier site work
and pre-assembly
Field assembly sequence is more restrictive due to installation hardware for the platens and would need to be determined prior to shipment of components.
HRSG Constructability
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HRSG Overview
Uprighting and Installing a Platen
Field Platen Approach
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HRSG Overview
Experience
Small-Size HRSGHamakua, Hawaii2 Pressure Level with Bypass System
Main Steam
Flow: 33.4 t/h
Press: 64.5 barg
Temp: 513 C
GT: GE LM2500
Fuel: Natural Gas
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HRSG Overview
Experience
Mid-Size HRSGNew Brunswick, Canada
Single Pressure with Fresh Air Firing Capability
Main Steam Conditions
Flow: 115 t/h
Press: 43.8 barg
Temp: 329C
Future LM 6000
Fuel: Natural Gas
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HRSG Overview
Experience
Large-Size HRSG Samalayuca, Mexico
3 Pressure Levels with Reheater + Supplemental Firing
Main Steam Conditions
Flow: HP 158.3 t/h
Press: HP 102.4 barg
Temp: HP 532C
GT: GE Frame 7FA
Fuel: Natural Gas
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HRSG Overview
Experience
Large-Size HRSGParis, Texas, USA
3 Pressure Levels with Reheater + Supplemental Firing
Main Steam Conditions
Flow: HP 226.8 t/h
Press: HP 124.3 barg
Temp: HP 568 C
GT: GE Frame 7FA
Fuel: Natural Gas