HRSG Overview.pdf

HRSG Overview

HRSG Overview

HRSG Systems - An Overview

HRSG Overview

Mechanical & Design Benefits

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

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

HRSG Overview


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


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

HRSG Overview

Section 3 Duct/Grid Burner System

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

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

HRSG Overview

Section 5 Emission Control Systems

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

HRSG Overview

Vortexes Used for Steam Separation and Circulation

Alternative : perforated sheets

Chevrons Used for Steam Purification

Alternative : mesh dryer

Section 6 Steam Drums

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

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

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

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

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

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.

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

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

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

HRSG Overview


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

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 Overview

Loading of Modular Box for Transport

HRSG Overview

Setting of Modular Box at Site

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 Overview

Field Modular Approach

Side Loading the first tube bundle in a Double Wide HRSG

HRSG Overview

Field Modular Approach

Close up of the showing degree of shop assembly

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 Overview

Uprighting and Installing a Platen

Field Platen Approach

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

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

HRSG Overview

Experience

Large-Size HRSG Samalayuca, Mexico

3 Pressure Levels with Reheater + Supplemental Firing


Flow: HP 158.3 t/h

Press: HP 102.4 barg

Temp: HP 532C

GT: GE Frame 7FA

Fuel: Natural Gas

HRSG Overview

Experience

Large-Size HRSGParis, Texas, USA

3 Pressure Levels with Reheater + Supplemental Firing


Flow: HP 226.8 t/h

Press: HP 124.3 barg

Temp: HP 568 C

GT: GE Frame 7FA

Fuel: Natural Gas

Documents

HRSG Overview.pdf