Research On Performance Of C+H Plasma Reactor

It is the research on performance of fluid flow and heat transfer of the hydrogen plasma reactor that play a very important practical significance in reaction conditions, the reactor design and optimization of industrial application for the acetylene yield by coal pyrolysis in hydrogen plasma.The temperature and velocity field of hydrogen plasma jet is hardly measured by the exiting technological means, therefore, the one of hydrogen plasma generator at exit was firstly calculated in this thesis. Based on assumption, the relationship of hydrogen plasma between dissociation and temperature was solved through combining thermodynamic equations and chemical equilibrium coefficient statistical expression. Considering the energy conservation law and the ideal gas state equation, the temperature and velocity at exit of hydrogen plasma generator were obtained under different conditions (the inlet temperature and velocity at reactor). Then, according to the different mixing way in the experiment, two types of hydrogen plasma reactor, A-type reactor and the B-type reactor, were defined. Through meshing the geometric model, setting up mathematical model, determination of hydrogen plasma and boundary conditions and choosing solving method to equations, the temperature field and velocity field in the two types of hydrogen plasma reactor were solved and analyzed comparatively. Besides, by defining three parameters, the effective volume coefficient, the effective length coefficient and the backflow coefficient, that reflect the performance of hydrogen plasma reactor, the influence of the two hybrid method on performance of reactor was studied , and finally it come to the conclusion that: the performance of A-type reactor is superior to the one of B-type reactor. On this basis, the influence of expansion-scale on the performance of A-type reactor was researched and come to a conclusion that, the smaller expansion is, the higher performance of A-type reactor is. In addition, the simulation of a typical operating condition indicates that the carrier gas at 50m/s have mixed well with the hydrogen plasma jet. Finally, in accordance with pilot-scale experiments on pyrolysis of the coal-acetylene using hydrogen plasma, a completely set of experimental system was designed, processed and debugged. The subsystems were tested firstly and then the operation of experimental system was adjusted to be stable before carrying out experiments. Next, the pulverized coal and the carrier gas were sent into the hydrogen plasma reactor and ran 15min's experiment. After that, drew the sample of pyrolysis coal and compared its particle diameters with the particle diameters of raw coal. Analytical results show that the A-type reactor performance is superior to the B-type reactor, confirming conclusions of numerical simulation.