Fired Heater Design

Fired Heater Design Popular

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Fired Heater Design Ver 1.6.zip

Fired Heater Design

Updated for Flownex 8.8 and later

Please note that the original fired heater model (ver 1) will no longer work with Flownex 8.8 and later. Therefore the model has been updated to version 1.6, please download this update.

The design of a fired heater (or similar) package typically starts with a heat and mass balance. This first step is necessary to determine the process parameters which determine most of the sizing of the package. A fired heater package heat and mass balance includes the modelling of the combustion process and the modelling of the heat transfer and fluid flow processes. Modelling the combustion process typically involves the specification of the fuel gas composition, the combustion air composition, the air-fuel ratio and the fuel flow rate. The heat transfer from the fired heater combustion process into the process fluid may be specified in terms of an overall heater thermal efficiency. Typical heat and mass balance calculations do not provide estimations of the physical size of the heater or even the ducting and other components such as combustion air fans. Neither do they enable the calculation of system pressure losses or heat losses. They are also incapable of providing insight into tube wall and process fluid film temperatures which are very important in the oil and gas industry. Flownex®enables the user to perform all these tasks easily and quickly in a single calculation.


The main purpose of this exercise is to size a fired heater (typically an API 560 design) and its associated combustion air fan and ducting. In order to perform this task efficiently, a Flownex®model has been developed which is able to model the combustion, fluid flow and heat transfer processes. As such the model relies on a fired heater compound component and a few scripts to handle fuel and flue gas analyses.


Using Flownex®, the design and sizing of the fired heater, combustion air fan and the associated piping and ducting could be performed inside of an hour. Furthermore, results such as process temperatures, tube wall temperatures, heat fluxes, flow velocities, pressure losses etc. could easily be obtained from the network. As an overall package sizing and design tool, Flownex®has proven to be far more efficient than other detailed design software.


The full case study discussion document is available on the Flownex® web page in the Case Studies section: