Improve On Invariable Temperature Calorimeter And Study On Coal Ignition With Excessive Oxygen

In order to supervise the quality of coal and control heat supply of cement manufacture, more and more cement factories apply invariable temperature calorimeter to measure calorific value of coal to stabilize production of cement and decrease consumption of energy. Through analysis and discussion on experiment theory and structure of calorimeter, the precision and veracity of apparatus can be efficiently enhanced with improvement on cooling emendation which is very important to calorific value measurement. Besides, with the help of invariable temperature calorimeter, ignition character of coal with excessive oxygen is studied.Based on analysis on determining principal and process, we particularly discuss caloric emendation during the course of measurement and apply Newton Cooling Theory to explain thermal exchange between inner and outer barrels due to temperature difference. Thermal exchange is key factor to influence caloric determination, and it will cause temperature dissipation in caloric measuring system during the course of measurement. Changing temperature velocity in inner barrel is not a stable constant, and it will vary with advancement of measuring from time to time, thus cooling emendation quadrature model is established to compensate temperature dissipation. From error of trapezia quadrature and hardware design of calorimeter, we introduce sampling factor to obtain factual temperature and adopt shorter interval to perform cooling emendation. The appropriate interval is confirmed through thermal capacity demarcating and caloric measuring experiments. The result indicates that improvement is helpful to enhance veracity of calorimeter.When coal combusts in bomb, temperature of measuring system will change. Through analysis and comparison graphs of temperature, we can see that they differ from each other with the variation of coal ingredient and there is a flexion in it. This flexion of graph can be defined as criterion of coal ignition character under excessive oxygen supply. Based on viewpoints of coal ignition, we put forward assumption aiming at ignition character of coal with excessive oxygen. In this thesis, with comparison of average temperature increase among eleven kinds of coal, the following are obtained: Homogeneous ignition happens when coal has higher volatile matter and there is a approximative direct-ratio relationship betweentemperature hoist before flexion and content of volatile matter; on the other side, heterogeneous ignition occurs for the coal with lower volatile matter content because of collective influence of volatile matter and fixed carbon combustion, and one-to-one relationship between temperature increase before flexion and content of volatile matter does not exit.