The Reasearch And Design Of Low Temperature Microwave Plasma Catalytic Reaction Of Hydrogen Production Sysytem

Energy conservation and environmental protection is the world’s issue. The U.S MIT’s studies show that mixing3%-5%content of hydrogen into the internal combustion engine could not only reduce the emissions of hydrocarbons and nitrogen oxides but also improve the combustion efficiency of the internal combustion engine. The onboard hydrogen technique can enhance the conversion rate of internal combustion engine and reduce the emissions by mixing hydrogen and fuel. Consequently, developing hydrogen technology with fast start-up, high conversion efficiency, volume miniaturization and intelligent control is of great significance.A microwave plasma hydrogen system is designed in this work, including plasma ignition and heating function. Ethanol is used to produce hydrogen, and the designed special shape of reaction and ignition cavity can ensure the process of heating and. Microwave power of ignition chamber and reaction chamber is controlled flexibly by the electrically adjustable reflector. The main conclusions can be summarized as follows:1. Three parts of experiment equipment hardware, system control and signal acquisition are designed for the microwave plasma hydrogen system. The experimental device consists of the design of experiment platform, piping system and microwave system. The controlled part provides the required temperature, pressure, pipeline gas flow rate. The signal of temperature, pressure and gas flow velocity is collected by the signal acquisition part.2. Based on the microwave electromagnetic field theory, the structure and properties of the microwave plasma reactor are analyzed, and the field equations of coaxial resonator is deduced. According to the size of the cavity, the electromagnetic distribution of field equation is obtained by using MATLAB. The required energy of hydrogen generation, plasma conductivity, dielectric constant, plasma frequency and the gas breakdown field strength are calculated according to amount of hydrogen, the pressure and temperature of the piping system. The results show that the designed system in this work could realize the plasma ignition and heating process of Ethanol reforming hydrogen reaction.3. The analysis and simulation of the ignition chamber and reaction chamber. Ignition chamber is optimized by HFSS software, and the optimal size is obtained. The highest electric field can reach to1.35×104V/m, which makes it easier for reactant gas to discharge. Reaction cavity is designed as coaxial cavity structure by CST software. The simulated results show that the S11scattering coefficient of-54and the electric field can reach to2.5×104V/m can be achieved. Quartz reaction tube is designed as helical structure, which can increase the reaction time, therefore, the reaction rate is improved.