Steel Plant Gas Pipeline System Transient Flow Analysis And Simulation

With the fast development of steel plants, the conveying capacity of gas pipe network systems of steel plants is greatly enhanced, and the structure of steel plants becomes more and more complex. The gases which are produced in steel smelting process are blast furnace gas (BFG), coke-oven gas (COG), converter (L-D) gas (LDG) and the mixture of them. The mission of gas pipe network systems is to transport these gases. However, the pressure of the gas pipe network is nonsteady. It can cause unsteadiness when users start to run or to close. Worse of all, large users' loads throw-off will cause transient flow. The hazard made by transient flow is serious. So it's necessary to study transient flow in gas pipe network systems of steel plants.Lots of scientific studies made before are mainly on transient flow in hydraulic pipe and natural gas pipe. Literature and report nearly can be found by now, which are about transient flow in gas pipe network systems of steel plants. In view of the status of research, this thesis presents theory of transient flow and devotes effort to the studies on transient flow in gas pipe network systems of steel plants.Chief achievements of the thesis are listed below:First, the basic conditions of steel plants are generalized, and the distributing configuration of gas pipe network systems is also analyzed. The species, components and flux of gas are also analyzed. It is generalized which contains species and gas production of gas sources, species and gas consumption of gas users, working process of gas holders and let out tower, gas consumption of self-supply power plant, etc. Boundary conditions of them are simplified. The basic configuration model of pipe network systems of steel plants is determined.Then, the solution of pressure and flux of single pipe in gas pipe network in steady state is confirmed, which bases on the configuration model of gas pipe network. The solution of pressure and flux of ring and tree-like structure are also discussed. Considering some specific conditions, the solution of parameters of boundary conditions are determined. The basic calculation model of steady flow in gas pipe network of steel plant is determined.Next, the basic process of transient flow is analyzed in the single pipe. Velocity of pressure surge is deduced. Several methods to solve transient flow are generalized, and typical linear equation of transient flow solution is deduced, with the pressure and the flux calculated in steady state as initial condition. The methods to confirm parameters of boundary conditions are discussed. The basic calculation model of transient flow in gas pipe network of steel plant is determined.Finally, the transient flow is simulated in single pipe, series pipe, branching pipe, and simple pipe network system of steel plant. The simulation result is also analyzed, and the rationality and accuracy of the theory in this paper are proved. According to simulation result, some suggestions and advices are offered to prevent transient flow in gas pipe network of steel plant.