improve fired heaters reliability with inclined firing system linkedin

Furnace

Improvements

Services

Improving Fired Heaters Reliability using Inclined

Firing Technology

Furnace Improvements

1

Furnace

Improvements

ServicesOperating and Reliability Issues

High tube metal temperatures

Localized flame impingement

Fired heaters have burners that are fired vertically upright, sideways or

downwards

FIS patented technology reorients the burners at a slight angle away

from the tubes

Hottest part of the flames and flue gases are moved away from the

tubes

www.heatflux.com 2

Furnace

Improvements

ServicesBenefits of Inclined Firing System

Significant reduction in tube metal temperatures

Low coking rates

Higher tube life and run lengths

Increased capacity possible in most heaters

Uniform firing achieved across the tubes

www.heatflux.com 3

Furnace

Improvements

Services

9/9/2014 www.heatflux.com 4

4'

BCD

12'-9"

TCD

12'-9"

INLET

OUTLET

4'

4'-4

2'-7"

4'

BCD

6'

5'

2'-7"

12'-9"

TCD

12'-9"

INLET

OUTLET

4'

Burners areinclined at5-10 deg.

Inclined Firing

System

INTERHEATER -2 INTERHEATER -1 CHARGE HEATER

35'-6" 35'-6"

5' 5'

6'

5' 5'

4'-6"

5' 5'

4'-6"

5-10deg.

Furnace

Improvements

ServicesInclined Firing System

www.heatflux.com 6

Height in

Elevation

BCD

0-0 8-0

5-0 7-1.5

10-0 6-3

15-0 5-4.5

20-0 4-6

25-0 3-7.5

8 burner systemTCD of 20-8

2'-7"

21'-9 1/2" I/S INS.

20'-8"TCD

8'-0"B.C.D.

7'-1 1/2"

B.C.D.

6'-3"

5'-4 1/2"

4'-6"

3'-7 1/2"

57

'-1

0" W

EL

D T

O W

EL

D L

EN

GT

H

61

'-4

1/2

"

45

'-8

5/8

"

5'-

0" 1

0'-

0" 15

'-0

" 20

'-0

" 25

'-0

"

10'-5"

I/S INS.

Furnace

Improvements

ServicesCase Studies

Case studies to be presented include:

Hot Oil Heater

Reformer Heater

Charge Heater, Vertical Cylindrical

Coker Heater

Crude Heater, Cabin Type

Crude Heater-Vertical Cylindrical

CFD Modeling carried out to demonstrate the benefits of Inclined

Firing System

www.heatflux.com 7

Furnace

Improvements

ServicesCFD Modeling

Start

CAD Geometry

CAD Geometry &

Meshing

Boundary

Conditions

Solver

Converged

Solution

Post Processor

Analysis

End

Diverge

Optimization

CFD

Computational Fluid Dynamics

Uses numerical methods and algorithms to study

fluid flow

Flow patterns in fired heaters, burners, fireboxes

3D models of fired equipment are created

www.heatflux.com 8

Furnace

Improvements

Services

Hot oil heater being built with 6 inclined burners ,commissioned in July 2014.

www.heatflux.com 9

Furnace

Improvements

Services

Hot Oil Heater

www.heatflux.com

Furnace

Improvements

ServicesFlue Gas Velocity Contours

Y-Plane

[ft/s]

Furnace

Improvements

ServicesFlue Gas Vector Plot

Long recirculation is observed.

Y-Plane

[ft/s]

Furnace

Improvements

ServicesFlame Contours (CO >2000 ppm)Colored by Temperature (o F)

[F]

Flame shapes are separate from each other.

[F]

Furnace

Improvements

ServicesFlame Contours (CO >2000 ppm)Colored by height (ft)

[ft]

[ft]

Furnace

Improvements

Services

Tube Metal Temperature Contours Wall Tubes

Tube Metal Temperatures Flue Gas Temperatures near Tubes

[F] [F]

Furnace

Improvements

ServicesWall Tubes Heat Flux Contours

Average Heat Flux on the Tubes:

10,482 Btu/hrft2

[Btu/hrft2]

Furnace

Improvements

Services

20'-0 7/8" (SHELL WIDTH)

24.0000

8 0.7500

113.0000 113.0000

4.0000 4.0000

24.0000

8 0.7500

EXISTING

4'-0"

2'-8 1/2"2'-8 1/2"

7.0000

5'-5" 5'-5"


24.0000

8 0.7500

113.0000 113.0000

4.0000 4.0000

24.0000

8 0.7500

PROPOSED

4'-0"2'-8 1/2"

2'-8 1/2"

7.0000

5'-5" 5'-5"

3.5o

3.5o

7.0000

C B

UR

NE

RL C B

UR

NE

RL C

BU

RN

ER

L

PROPOSED INCLINED BURNER

EXISTING PROPOSED20'-0 7/8" (SHELL WIDTH)

24.0000

8 0.7500

113.0000 113.0000

4.0000 4.0000

24.0000

8 0.7500

EXISTING

4'-0"

2'-8 1/2"2'-8 1/2"

7.0000

5'-5" 5'-5"


24.0000

8 0.7500

113.0000 113.0000

4.0000 4.0000

24.0000

8 0.7500

PROPOSED

4'-0"2'-8 1/2"

2'-8 1/2"

7.0000

5'-5" 5'-5"

3.5o

3.5o

7.0000

C B

UR

NE

RL C B

UR

NE

RL C

BU

RN

ER

L

PROPOSED INCLINED BURNER

Down Fired Steam Reformer

Furnace

Improvements

ServicesVelocity Vectors on Center Plane

In the proposed case, velocity vectors clearly show improvement in the flue gas flow

pattern with no direct contact of high velocity vectors on radiant tubes.

Base Case Proposed Case

[ft/s]

Furnace

Improvements

ServicesTemperature Contours on Center Plane

High flue gas temperature

going towards the tubes.

High flue gas temperature

going away from the tubes.

Base Case Proposed Case

In the proposed case, temperature contours clearly show the reduction in the flue gas

temperature around the radiant tubes.

[F]

Furnace

Improvements

Services

Charge Heater with 6 Burners

Furnace

Improvements

ServicesFlue Gas Temperature Contours

Central Plane

[F]

Temperature

near the

tube is high.

Flame angled

towards the center of

the furnace / away

from tubes.

Existing Case Proposed Modification

Furnace

Improvements

ServicesFlue Gas Temperature Contours

Plane

Location


Temperature

near the tube

is high.

[F]

Furnace

Improvements

ServicesFluid Path Lines: from Fuel Inlet


Outer

recirculation

pattern

[ft/s]

Furnace

Improvements

ServicesFlame Contours (CO >2000ppm)

[F]


Colored by Temperature

[F]

Furnace

Improvements

ServicesFlame Contours (CO >2000ppm)

[ft]

Flame height is14 ft. Flame height is reduce to 9 ft.


Colored by Height

[ft]

Furnace

Improvements

ServicesFlame Contours (5% O2)

[ft] Existing Case Proposed Modification

Flame

height

is16 ft.

Flame height is

reduce to 9.8 ft.

Colored by Height

[ft]

Furnace

Improvements

ServicesFlame Contours (3% O2)

[ft]

Flame height is 15.2 ft

at 3% O2.

Colored by Height

[ft]

Furnace

Improvements

ServicesTube Metal Temperatures

[F]


Hot spots due

to flame

impingement.

TMTs more

uniform.

Furnace

Improvements

ServicesTube Heat Flux

High heat flux

distribution at

bottom of the

tubes


[Btu/hrft2][Btu/hrft2]

Furnace

Improvements

ServicesCoker Heater

High tube metal temperature issues

Fuel gas fired low NOx burners

www.heatflux.com 30

Furnace

Improvements

ServicesCoker Heater Geometry

www.heatflux.com 31

ProposedExisting

Burners are

inclined by

7.5 towards the walls.

Furnace

Improvements

ServicesVelocity Vectors

www.heatflux.com 32

Expanded View[ft/s]

Plane at primary tip

Furnace

Improvements

ServicesVelocity Vectors by Temperature

www.heatflux.com 33

[F]

Plane at primary tip

Furnace

Improvements

ServicesTube Metal Temperature Contours

www.heatflux.com 34

[F]

Furnace

Improvements

ServicesRefractory Temperature Contours

www.heatflux.com 35[F]

Furnace

Improvements

ServicesFlame Shapes (Iso-Surface of

CO 2000 ppm)

36Colored by Temperature [F]

B-4B-1 B-2 B-3

Furnace

Improvements

ServicesFlow Profiles - Vertical Up Firingvs Inclined Firing

www.heatflux.com 37

Inclined Firing Vertical Up Firing

[ft/s]

Furnace

Improvements

Services

Flue Gas Temperature Profiles Vertical Up Firing vs Inclined Firing

www.heatflux.com 38

Inclined Firing Vertical Up Firing[F]

Furnace

Improvements

ServicesFlame Profiles - Vertical Up Firing

vs Inclined Firing

www.heatflux.com 39

Inclined Firing Vertical Up Firing

Furnace

Improvements

ServicesCrude Heater Horizontal Cabin

Cabin heater suffering from high tube metal

temperatures at arch

Originally 6 large burners-30 MMBtu/hr

each

Proposed 36 burners-5 MMBtu/hr each with

inclined firing mode

Furnace

Improvements

ServicesFlames Colored by Height

CO 2000 PPM

Base Case Proposed Design[ft]

Furnace

Improvements

ServicesVelocity Vectors - Z-1 Section

Base Case Proposed Design

Z-1Z-1

Z-2 Z-2

[ft/s]

Furnace

Improvements

ServicesTemperature Contours at Z Sections

Base Case Proposed Design[F]

Furnace

Improvements

ServicesRadiant Tube Temperature

Contours

Base Case Proposed Design

[F]

Furnace

Improvements

ServicesCrude Heater- Vertical Cylindrical

Client facing flame impingement and high tube

metal temperatures in radiant

section

FIS recommended inclined burner firing system to eliminate

flame impingement

Carried out CFD modeling of the burners and radiant section

to demonstrate the benefit of the

inclined burner firing system

www.heatflux.com 45

Furnace

Improvements

ServicesExisting Burner Arrangement

EXISTING FLOOR & PLENUM ARRANGEMENT

www.heatflux.com 46

Furnace

Improvements

ServicesInclined Firing System Burner Arrangement

www.heatflux.com 47

Furnace

Improvements

Services

Crude HeaterFloor Design

www.heatflux.com

Furnace

Improvements

Services

Crude HeaterPlenum Chambers

www.heatflux.com

Furnace

Improvements

ServicesVelocity Vectors

Base Case vs Inclined Firing System

www.heatflux.com 50

0 ft

Height in

Feet

19 ft

36 ft

50 ft

[ft/sec]

Existing Case

with Vertically Fired

Burners

Proposed Case

with Inclined Firing

System

Furnace

Improvements

ServicesTemperature ContoursBase vs Inclined Firing System

Base Case Inclined Firing System

www.heatflux.com 51

[F]

Furnace

Improvements

ServicesTemperature Contours at 10ftBase Case vs Inclined Firing System


At 10 ft At 10 ft

www.heatflux.com 52

[F]

Furnace

Improvements

ServicesTemperature Contours at 15 ft -



1

At 15 ft At 15 ft

www.heatflux.com 53

[F]

Furnace

Improvements

ServicesCO Mass Fraction Contours at 10 ftBase Case vs Inclined Firing System

At 10 ft

Inclined Firing System

1

Base Case

At 10 ft

www.heatflux.com 54

[ppm]

Furnace

Improvements

ServicesCO Mass Fraction Contours at 15 ft


At 15 Ft

Inclined Firing System

1

Base Case

At 15 Ft.

www.heatflux.com 55

[ppm]

Furnace

Improvements

Services

Iso Surface of CO MF 2000 PPM Colored by Temperatures



Top Viewwww.heatflux.com 56

[F] [F]

Furnace

Improvements

Services

Iso Surface of CO Mass Fraction 2000 ppm Colored by Flame Height

Base Case Inclined Firing

System

www.heatflux.com 57

[ft]

Furnace

Improvements

ServicesRadiant Wall Temperatures

Base Design Proposed Design

For h =100 Btu/ft2h and T= 800 F

www.heatflux.com 58

[F]

Furnace

Improvements

ServicesSummary

Client reported almost 250 F reduction in tube metal temperatures after the

revamp.

Inclined Firing is proven in solving high tube metal temperatures problems

CFD modeling demonstrated the ability of IFS to improve performance

FIS is ready to evaluate your heater to determine whether it is a suitable

candidate for Inclined Firing at no cost. www.heatflux.com 59

Furnace

Improvements

ServicesDHT Heater

Installation of 4 burners in inclined firing pattern

www.heatflux.com 60

Furnace

Improvements

Services

DHT HeaterFloor Layout

www.heatflux.com

Furnace

Improvements

ServicesSEU Units

www.heatflux.com 62

F-4202 F-4201

1650 2350

(TYP.)

3

(TYP.)

5.5

C B

UR

NE

R

C B

UR

NE

R

3200 (P.C.D.) 3962 (P.C.D.)

762 1372

B.C.D. B.C.D.

FLOOR PLT. FLOOR PLT.

L

L

C B

UR

NE

R

C B

UR

NE

RL

L

Furnace

Improvements

ServicesVertical Cylindrical Heaters

Two vertical cylindrical heaters working for almost 3 years with Inclined Firing System

Reduced fouling and hot spots

Provided 10% extra capacity

with Inclined Firing Technology

Furnace

Improvements

Services

Reboiler Heaters

www.heatflux.com

Furnace

Improvements

Services

We hope you found our presentation helpful and informative.

www.heatflux.com 65

improve fired heaters reliability with inclined firing system linkedin

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