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04/13/23 Furnace 1

Study Objectives

• Identify ways to eliminate flame impingement on the tubes and reduce tube metal temperature in radiant section

• FIS has recommended the following modifications:– Bring Burners Closer to the Center by about 1-2 ft..– Incline burners by 5 towards the center

• Carry out CFD Modeling of the Burners and Combustion Chamber to demonstrate the benefits of the proposed modifications

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Existing Burner Arrangement Elevation

04/13/23EXISTING FLOOR & PLENUM ARRANGEMENT

Furnace Improvements

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Velocity Vectors at 45 degBase Case vs. Proposed Case

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Temperature Contours at 45 degBase Case vs. Proposed Case

Base Case Proposed Case

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Temperature Contours at 5ft Base Case vs. Proposed Case

Base Case Proposed Case

At 5 ft.At 5 ft.

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Temperature Contours at 10ft Base Case vs. Proposed Case

Base Case Proposed Case

At 10 ft.At 10 ft.

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CO mass fraction contours (PPM) at 10ft Base Case vs. Proposed Case

At 10 ft.At 10 ft.

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CO mass fraction contours (PPM) at 15ft Base Case vs. Proposed Case

At 15 ft.At 15 ft.

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Path lines colored by temperature (o F)- Base Case vs. Proposed Case

Base Case Proposed Case

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Iso surface of CO mass fraction 2000 PPM coloredby flame height (ft.)- Base Case vs. Proposed Case

Base Case Proposed Case

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Summary

• Base case has the recirculation region at center of heater, there by diverting the flow towards the radiant tubes.

• Proposed Case has no recirculation zone between opposite burners there by no bending of flame is observed

• Due to above reason flame length is increased for 20 ft(for base case) to 24 ft. for Proposed Case

• High temperatures are confined to center of heater • Flame impingement is eliminated