Autogenous Ignition Temperature Tester Development Under High-pressure Oxygen-enriched Environment

Dangerous chemicals pose potential threat or actual harm to personal safety and property security in all aspects of life cycle due to the inherent danger of physical and chemical properties. However, the autogenous ignition temperature has a great relationship with the ambient pressure substance, oxygen content and size of the container. Existing test equipment, testing is only under normal atmospheric, and can not complete measurements under different pressure in oxygen-rich conditions.This dissertation explored the influencing factors of spontaneous combustion based on Semenov theory of spontaneous combustion heat. It focused on the high-precision uniform temperature generating technology, gas ratio technology and autogenous ignition temperature capturing technology and developed an autogenous ignition temperature tester for high-pressure and oxygen-enriched atmosphere which achieved automatic detection of autogenous ignition temperature under controlled heating rate, accurately and security. As following:Firstly, this dissertation based on comprehensive understanding of autogenous ignition temperature test testers and test methods, gave the overall design, analyzed the key factors which affect the accuracy of the autogenous ignition temperature measurement, such as high-pressure and oxygen-enriched environment generating device, heater power and arranged location, designed a cylindrical high temperature and pressure testing room. At the same time, it designed the gas ratio system and the autogenous ignition temperature capture system according to the standard. Achieve detection of autogenous ignition temperature in high-pressure and oxygen-enriched atmosphere.Secondly, this dissertation designed the hardware system. The hardware based on ATmega128 MCU as the core, mainly comprised main control unit, heating unit, heating unit, human-computer interaction unit and gas ratio unit. And it analyzed the compensation for temperature cold side during testing process. It improved the accuracy and stability of temperature detection significantly. Software used the modular design method, including heating rate control which was depending on PID control algorithm in small zone as the core, gas ratio which was depending on Daltons law of partial pressures, human-computer interaction and data communication.Finally, with the analyzing of a lot of experimental data, it tested the temperature measurement accuracy and the temperature control accuracy of the tester. And it improved the device according to the actual situation. Finally, summarized some problems of the device and made prospects.Experimental results show that, temperature deviation is less than 10%; Testing result has a good repetitive. The experimental data standard deviation is better than 1℃. The system has high reliability and stability, and can meet the actual demand.