Structure Design And Performance Analysis Of Chemical Reformer

The chemical recuperated gas turbine (CRGT) is a new kind of advanced cycle which can use the exhaust heat.It can improve gas turbine efficiency and reduce the gas turbine exhaust levels of NOx significantly.The object of study is the core component of CRGT—chemical reformer.It is aimed to design the structure of chemical reformer.As the basis of its structure,simulation studies are conducted to analyze its performance, then find the factors that affect the reformer's performance and the influence principles.The main contents of this paper can be divided into three areas which are contacted with each other:simulation of chemical reformer, numerical simulation of the chemical reformer, structure optimization design of the chemical reformer.Simulation, general-purpose simulation software Matlab/Simulink is utilized in this paper. Adopting modular modeling idea,simulation model of chemical reformer is established as the basis of mathematical model of chemical reformer.The performance of chemical reformer under different working conditions is compared and analyzed.Reactant gas composition response principle to the change of gas inlet temperature,reactant gas inlet temperature, water carbon ratio and pressure is gained. Numerical simulation,Gambit is used to plot the modelmesh.Computational fluid dynamics software Fluent is used to numerical simulate a single finned tube flow field to analyze the status of fin-tube heat exchanging. Matlab is used to iterative calculate the reaction bed temperature drop and the product gas composition which is substituted into the numerical simulation of next level of the finned tube. Finally, the total quantity of heat exchanging is gained, as well as response principle of the single-stage heat exchange, the reaction bed temperature drop, hydrogen content to increases of the level.Structure, thermal calculation is conducted for thermal heat transfer coefficients. Combined with the total quantity of heat exchanging and the average logarithmic temperature difference which are gained by numerical simulation before, the heat transfer area can be calculated. A suitable mode of finned tube arrange is utilized to make sure that the heat transfer area in design is larger than the calculated heat transfer area.Finally, structure optimization design program of chemical reformer is gained, and the Three-dimensional model of chemical reformer is established.