Research And Development Of High Temperature Air Generator And Design Of High Temperature Air Gasifier

This research has been implemented as one of activities of projects "Research on high temperature air gasification (HTAG) for biomass" (863 scheme) and "Research on process of high-temperature air/vapor gasification for municipal refuse disposal" (invested by Zhuzhou Torch Industrial Furnace Inc., Hunan Province). This thesis aims to improve the performances of the former high temperature air generator, and to obtain knowledge on its operation, and then to design and manufacture a gasifier utilizing high-temperature air as gasified medium preheated by this generator.Two serious problems emerged during the experiment of the former high-temperature generator. The first was the pressure drop throughout the air supply system is up to 2530Pa, which caused the total air flow rate is much lower than the design standards. To overcome this problem, measures such as increasing the pipe diameter and the plug stroke of electromagnetic valve and optimizing pipe layout have been put forward. It has been verified that the new air supply system achieved 23% reduction in total pressure drop. The other was the difficulties in ignition and sequent deflagration within the high temperature air generator. By rearranging the portfire, reliable ignition has been fulfilled.Hot tests have been carried out. Results show that the heating-up rate of the generator is 260 C/h. The emission of nitrogen oxide is 200ppm. The air component isn't influenced by the residual fume at the switching moment.The steady-state model of heat transfer has been established. Theeffects of main factors such as the fuel flow rate on the flow ratio and temperature of high temperature air are studied. Researches indicate that the flow rate of high-temperature air is increased as the fuel flow rate is increased in the case of the same temperature, and decreased slowly as the air temperature is increased under the fixed fuel flow rate.A high-temperature air/vapor gasifier has been designed. The synthetic calculation method is employed to complete the calculation for design of gasification technics. Both the calculation and the design of the gasfler structure are also presented in detail.