Xfh® Ultra

Leading-edge software for rating and simulating fired heaters

Xfh Ultra
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Xfh Ultra, HTRI’s general-purpose fired heater modeling software, provides calculations for refinery operations. Users can easily explore operating scenarios to increase capacity and performance, helping to minimize energy loss and shutdown time.

Xfh Ultra is flexible enough to handle most fired heater configurations. In each firebox, heat transfer is simulated using a single-zone model. This reliable and practical approach is combined with an integrated convection section calculation with allowance for shock radiation from the firebox.

The graphical interface makes it easy for users to quickly set up and run fired heater cases. During testing, users rated it easiest to operate when compared to other fired heater software. It features an interactive fired heater diagram, which simplifies the setup of complex stream and coil connections.

Xfh Ultra tubeside calculations are based on HTRI’s methods for calculating heat transfer and pressure drop in process fluids, as used by Xchanger Suite®. These methods are backed by HTRI’s extensive research on single-phase and two-phase boiling. In addition, the program uses well-established single-zone methods for simulating the firebox and a 3D incremental approach to modeling flue gas temperatures in the convection section.

What's new in Version 4.0

  • Air preheaters: Xfh Ultra simulations now include an air preheater module option that uses flue gases to heat the combustion air supplied to the firebox burners. Preheating combustion air in fired heaters and furnaces provides greater thermal efficiency and increases combustion temperatures. Users can base air preheater calculations on a preheater exchanger UA value or target preheated air temperatures.
  • Detailed flue duct calculations: Users can specify details of the flue gas ducting between any flue gas-side components (i.e., fireboxes, convection banks, air preheaters, flue gas mixers, and stacks). Doing so allows the program to evaluate the impact of these items on the draft and heat loss from the heater. Any detailed flue duct can consist of several sections made up of straight ducts, bends, transitions, K-factor resistances, and simple, fixed ΔP fans.
  • Improved heat loss calculations: Full heat loss calculations, accounting for conduction through multiple insulations layers, can be specified for all fireboxes, convection banks, flue ducts, and stacks.
  • HTRI SmartPM connection: Connections to SmartPM, HTRI's software for monitoring and performance prediction of fouling in heat exchanger networks, are improved.
  • Fouling calculation mode: In this mode, intended for use within SmartPM for data reconciliation, the program determines levels of tube fouling in the heater from the performance of the heater together with fully specified fuel flows. This calculation mode is valuable for monitoring the performance of a heater over an extended period.
  • Coil bypasses: Users can specify a percentage of the total tubeside flow, which bypasses any given coil. The bypassed flow is unheated and is remixed with the main non-bypassed flow after the coil.
  • Peak convective heat flux multiplier: Users can specify a multiplier for calculation of peak convective flux from the average convective flux based on experience and/or application.
  • Customizable property imports: In previous versions, the program used fixed ΔP and ΔT in the property table for fluid properties imported from a process simulator. With customizable imports, users can specify multiple pressure and temperature ranges with different ΔP and ΔT values. This capability is important in vacuum heaters that may require small increments of ΔP at the low-pressure end.
  • .NET Core: Version 4.0 targets the .NET Core version .NET 6.

Contact us at [email protected] for more information about Xfh Ultra.

Xfh Ultra multiple firebox arrangement
Multiple firebox arrangement (typical of catalytic reformers) set up using the Xfh Ultra interactive configuration diagram.
Xfh Ultra 3.0 inside the UniSim Design process simulator
Xfh Ultra 4.0 inside Honeywell UniSim® Design Suite process simulator
(The screenshot of UniSim Design on the right is used with permission of Honeywell International SARL)