(中南大學(xué) 能源科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 以圓形蓄熱式熔鋁爐為研究對象，根據(jù)熔鋁爐的運行特點，應(yīng)用標(biāo)準(zhǔn)k—ε湍流模型、渦耗散模型、P-1輻射模型描述湍流燃燒過程，應(yīng)用等效比熱法描述鋁料的熔化過程，對熔鋁爐內(nèi)進口與出口邊界交替變化的熱工過程進行非穩(wěn)態(tài)多場耦合數(shù)值模擬研究。蓄熱式熔鋁爐基準(zhǔn)工況下的數(shù)值模擬結(jié)果表明：與傳統(tǒng)單一燒嘴工作相比較，兩個燒嘴快速切換，鋁料溫度分布更為均勻，其平均溫度在前3 h升溫較快，隨后由于熔化吸熱升溫速率逐漸減小。以縮短鋁料熔化時間為目標(biāo)，采用正交試驗方案，對影響熔鋁爐熱工過程的5個參數(shù)進行數(shù)值模擬優(yōu)化，其優(yōu)化工況為燒嘴高度657 mm、燒嘴傾角25°、燒嘴夾角90°、過剩空氣系數(shù)1.1、空氣預(yù)熱溫度800 ℃。與設(shè)計工況相比，優(yōu)化工況能縮短鋁料熔化時間1 h，可降低能源約20%。
關(guān)鍵字: 熔鋁爐；正交試驗；數(shù)值模擬；優(yōu)化
（School of Energy Science and Engineering, Central South University, Changsha 410083, China）
Abstract:A numerical model of a cylindrical regenerative aluminum melting furnace was developed according to its operation characteristics. By including the standard k—ε model, the species transport model and the P-1 radiation model to describe the turbulent combustion process in the furnace, and applying the equivalent specific heat method to describe the aluminum melting process, a transient and multi-fields coupled simulation was carried out to investigate the thermal alternation processes in the inlet and outlet areas of the furnace. The simulation results of the standard operation case show that, compared with the traditional operation with one burner, a more uniform temperature distribution can be achieved in the switch operation of two burners. In particular, the temperature rises quickly in the first three hours, followed by a slower rising due to heat absorbed by the melting alumina in the furnace. More simulations were carried out based on the orthogonal design to optimize the main five parameters that have significant influences on the process. The results indicate that an optimal operation condition can be achieved with the burner height of 657 mm, the vertical burner angle of 25°, the horizontal angle between two burners of 90°, the excess air coefficient of 1.1 and the air preheating temperature of 800 ℃. Compared with the result of the standard operation case, one hour can be reduced in the melting time of the alumina in the optimal condition, which is equivalent to 20% reduction in the energy consumption.
Key words: aluminum melting furnace; orthogonal experiment; numerical simulation; optimization
