Research On Gas Flow And Thermal Engineering System In Regenerative Continuous Reheating Furnace

High Temperature Air Combustion is a high-effective combustion technology formed in 1990s. As an application of HTAC to heating furnace, regenerative heating furnace developed rapidly in middle and small steel industries through recycling the waste heat of flue gas and burning BFG, and the double effects of lowering the specific fuel consumption and decreasing the loose of BFG can be obtained. Recently, as the increasing of fuel type, preheating mode and productivity, the energy saving effect and application of regenerative furnace in big steel industries have been influenced. To solve the problems as unlikeness water equivalent of fuel gas and preheating gas, high and fluctuant furnace pressure and deficiency of heat storage capacity of regenerator, etc., the paper is mainly about gas flow regulation and thermal system of regenerative heating furnace and a recuperative and regenerative heating furnace with slide flue was exploited.Experimental study on the problems as pressure system along flow direction, pressure fluctuate pressure and puffing and inhaling at furnace door is carried out, and then the furnace pressure distribution regulation and its influencing factors are obtained. Some conclusions are therefore drawn as follows. It is conclude that gas flux, outlet port suction and switch mode are the key factors on pressure characteristic. With steady furnace style, gas flux decreases tends to decrease furnace pressure and pressure difference along gas flow; large outlet port suction can change the whole pressure though pressure distribution not changed; the pressure is uniformed with decentralizing switch than centralizing switch. The area ratio of burner inlet to furnace hearth and assistant flue area are the key factors on pressure characteristic. With steady furnace's operating, increasing the area ratio of burner inlet to furnace hearth or the area ratio assistant flue of to burner inlet tends to lower pressure. So, furnace pressure can be improved by assistant fuel. Theoretical and experimental study is carried out around pressure fluctuation. Some conclusions are therefore drawn as follows. The furnace pressure adjustment can be implemented automatically by piping system with small thermal load and can't be implemented with large thermal load. By analysis about puffing and inhaling, it is found that the problem about puffing and inhaling cannot be resolved only by increasing pumping.Theoretical and testing study on heat transfer performance of regenerator is carried out around the relation between the constructional and operating parameters and thermal index, and then the heat performance of regenerator and its influencing factors are obtained. Some conclusions are therefore drawn as follows. Among the operating parameters, heat transfer performance of regenerator is mainly affected by gas flow. With steady regenerator construe, increasing gas speed trends to decrease gas heating temperature and increase fuel gas temperature and decrease thermal efficiency of regenerator. Among the constructional parameters, heat transfer performance of regenerator is mainly affected by regenerator height. With steady regenerator operate, increasing regenerator height trends to increase gas heating temperature and decrease fuel gas temperature and increase thermal efficiency of regenerator. But increasing regenerator height trends to increase pressure loss in the regenerator and decrease pressure in front of burner, and then power consumption is augmented and combustion is affected.Regenerative and recuperative reheating furnace is carried out, and heating systems of regenerative-recuperative furnace are compared independed on thermal value theory, such as regenerative burners abutting against feed end and recuperative burners abutting against discharge end or regenerative burners abutting against discharge end and recuperative burners abutting against feed end. Effect of the two heating system is analyzed by pure thermal value equation. The results show that thermal value of regenerative burners abutting against feed end and recuperative burners abutting against discharge end is large and heat utilization is reasonable.Layout about Ansteel rolling system is established. Reheating furnace colony in layout is made up of by regenerative-recuperative furnace, regenerative continuous reheating furnace and recuperative furnace. Then No.1 recuperative furnace in Ansteel rolling system about 1780 product line was reconstructed to regenerative-recuperative furnace. The specific heat consumption reduces from 1.45GJ/t to 1.22GJ/t and power consumption increases from 0.014GJ/t to 0.033GJ/t after furnace reconstruction and fractional energy saving is 14.7%.