GPC Control on Exhaust Gas in Regenerative Furnace Based on Feedforward of Hearth Temperature and Air Flow

Exhaust temperature is an important indicator in regenerative furnace with characteristics of nonlinearity, time-varying and large inertia. Also, it is affected by the hearth temperature and flow rate of combustion air, which makes it hard to be well controlled by traditional methods, such as PID and etc. In this paper, a strategy of generalized predictive control (GPC) integrated with feedforward of hearth temperature and air flow is presented to optimize the exhaust temperature control. Practices show that the control index is more stable and errors are obviously narrowed.

Research on the Flow Character of Regenerative Heating Furnace Affected by the Switching Model

On the basis of wholly analyzing the mechanism of the heat transfer in the 1880 regenerative furnace, the physical and mathematical 3-D model was set up to describe the heat transfer and combustion in the furnace, and the CFD software was used to simulate the whole combusting process in detail. From this, the law of the flow affected by four classical switching modes was studied in emphasis. The conclusions in the study were helpful to the reasonably design and optimization controlling of such furnaces.

Experimental Study on Decarburization in Heavy Rail Manufacturing Process

Through the metallurgical testing on a lot of samples from different parts of the heated slab and the finished product in heavy rail manufacturing process, analysis on the surface decarburization characteristics of U71Mn and U75V is carried out. Through analyzing the main affecting factors on the decarburization depth of heavy rail in the heating and rolling process, some effective means to reduce the product surface decarburization are put forward. The results show: (1) The surface decarburization depth distribution of heavy rail slab heated in the regenerative furnace is seriously imbalanced, and the fluctuation ranges between 30% -40%.(2) Under the same production conditions, decarburization of U75V is serious, and the average depth of U75V is more than 11% higher than the U71Mn. (3) The rolling process in the production of heavy rail has a great influence on the distribution of the surface decarburization depth. (4) Because the deformation rate of rectangle slab in the rolling process everywhere is different, in order to reduce the decarburization depth of finished product, it is useful to select the narrow surface of slab to generate the head of heavy rail, as well as to change the structure of the slab cross-section from right-angle to arc.