| Autor: |
A. Z. S. Chong, John Ward, Robert J. Tucker, Sara A. C. Correia-Eicher, Jeff Rhine |
| Rok vydání: |
2008 |
| Předmět: |
|
| Zdroj: |
Volume 3: Combustion Science and Engineering. |
| DOI: |
10.1115/imece2008-67216 |
| Popis: |
The replacement of part of a conventional refractory lining in a furnace by a porous ceramic panel can enhance the thermal efficiency and increase the furnace throughput. If the hot furnace exhaust gases are passed through the panel (instead of leaving through the normal exhaust) heat is transferred, largely by convection, to the fine porous structure. Most of the heat which is recovered in the porous refractory in this fashion is then re-radiated back into the furnace chamber so that the overall radiative heat transfer to the load is substantially enhanced. The paper describes the development, validation and application of a mathematical model which simulates the installation of such a panel in an intermittently operated, gas-fired furnace heating steel bars to temperatures of approximately 1200°C. The overall model iteratively linked a sub-model of the flow and heat transfer through the porous section with a transient zone model of the radiation heat transfer in the furnace chamber. This procedure is then repeated sequentially throughout the period of the furnace operating cycle to predict the overall thermal performance of the furnace. The model was validated by measurements obtained during a series of tests on a gas-fired furnace. The predicted load temperatures and furnace energy consumptions were in good agreement with the corresponding measurements and indicated that reductions in energy consumption of up to 20% can be obtained depending upon the method of operating the furnace. Following the successful validation of the model it was then employed to predict the thermal behaviour of a small furnace heating steel bars or billets from a “cold start up”. The radiative heat transfer to the load was significantly enhanced throughout the heating period and this led to substantial improvements in the thermal efficiency and reductions in the time required to heat the load to its specified discharge temperature.Copyright © 2008 by ASME |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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