One way to design utility boilers with high thermal efficiency is to improve their furnaces — the most important part in their energy conversion process. Studying furnaces in utility boilers requires engineers to account for radiation, which can be difficult to solve for analytically and expensive to study experimentally.
Optimizing the performance of large power plant boilers, for instance, is a common area of study. Today, we focus on one boiler design element in particular: A retired scotch marine boiler with two coal-burning furnaces. Image by Andy Dingley — Own work. Radiation is the key heat transfer mechanism in boilers. Radiation is difficult to predict, and its complexity and dependence on the enclosure geometry means that analytical solutions exist only for very simple problems.
Further, experimental modeling of furnace enclosures is expensive.
As an alternative, engineers can build numerical models to properly analyze such enclosures and evaluate thermal efficiency. This is a practical choice, as utility boilers often include thin obstacles, like panels, hanging in the radiation chambers.
For our simulation, we model the obstructions as baffles with zero thickness to reduce the mesh and computational cost. The obstacles each contain an emitting-absorbing medium. The obstructions in the utility boiler model. For our assumptions, we draw from existing research by P.
As for solving our model, we use the discrete-ordinates method DOM. This method is well suited for cases that involve radiation absorption and scattering in a cavity with a moderate optical thickness.
We end up with a set of 24 Fired heater simulation dating directions that represents radiative intensity transport. For more details on how we set up this model, including our use of the radiative transfer equation RTEboundary conditions, and the different quantities used in the model, refer to the model documentation.
Using the model presented here, we can easily find the radiative heat flux behavior both inside the furnace and on its surfaces as well as compute the radiative intensity in the participating media.
Further, we can Fired heater simulation dating our results to those from the reference for various configurations. For example, the simulation below, which analyzes the predicted outgoing heat flux, is in good agreement with the published data.
This helps confirm the validity of our simulation analysis. The outgoing heat flux on the boiler walls.
Hi, I have problem modeling radiation heat transfer in a slab. A constant radiation hits an slab and part of that id transferred through the slab, part is absorbed within the slab and part is reflected. How should I model this? There are a lot of complicated models answered but none of them works for this.
Could you please give some information? You can fix this by pressing 'F12' on your keyboard, Selecting 'Document Mode' and choosing 'standards' or the latest version listed if standards is not an option. Predicting Temperature and Heat Flux in the Furnace Using the model presented here, we can easily find the radiative heat flux behavior both inside the furnace and on its surfaces as well as compute the radiative intensity in the participating media.
Get the Utility Boiler Tutorial. Post Tags Heat Transfer Module. Q I am considering a flueless gas fire for my modern house, which is a focal point (simulated coals) fire, with a bit of heat coming from Fired heater simulation dating.