Baiqian Dai

Experimental Study on Rich Oxygen Gasification and Ash Character in Entrainedflow Coal Gasifier

Entrainedflow Gasifier with Large Capacity and Slagging Tap is Usually Use for IGCC and Largescale Chemical Industrial Factory. while, there are 57% of Reserved Coal is Highfusion Temperature Coal, which Cannot Satisfy the Requirement of Thegasification for Slagging Tap. . Therefore, Two Typical Kinds of Chinese Coals Wereselected and Gasified in a Lab-Scale down-Flow Gasifier with Feeding Rate Ataround 1kg/h. the Results Show that along with the Increasing Temperature, Thecarbon Conversion and Cold Gas Efficiency will be Increased Quickly Whentemperature is below 1400°C, and then Increased Slowly when above 1400°C. the Optimum O/C Molarratio is around 1:1, the Cold Gas Efficiency and Carbon Conversion under Thisexperimental Condition (1300-1400°C) are Separately 31% and 80%. at the Optimumgasification Condition, Increasing the Residence Time will also Increase Thecoal Gas Concentration, Carbon Conversion and Cold Gas Efficiency. under Thisexperimental Condition, the Best Residence Time is at Least 1.5~2.0s.

Experimental Study on Ash Melting Behavior of Xinjiang High-Alkali Coal Blended with Low-Alkali Coal During Coal Combustion

In this study, one typical Xinjiang high-alkali coal (HA coal) and another low-alkali coal (LA coal) have been mixed to study the ash melting behavior as a function of coal blending ratio, through the use of AFTs, XRF tests of samples. Moreover, the thermodynamic equilibrium calculation and ternary phase diagram CaO–SiO2–Al2O3 analysis were also used to clarify the mechanism of blended coal ash melting behavior and to optimize the coal blending ratio. The results indicate that the trend of AFTs is not linearly related to the blending ratio of coal mixtures. Instead, it is highly linked with the changes on the liquidus temperature from the ternary phase diagram systems. The initial melting temperature of HA coal ash is approximately 275 °C lower than that of LA coal ash due to the existence of alkali and alkaline metals, although it has relative higher ash fusion temperature. The mixing of LA coal is not only beneficial to reduce the amount of vaporized sodium, but also increases the initial melting temperature of blended ash due to the physical and chemical reactions between alkali and silica particles.

Experimental study on low NOx emission using blast furnace gas reburning and industrial application in stoker boiler

In order to get some useful information on reforming one stoker boiler with the capacity of 75t/h by using gas reburning technology, the effect of some key factors such as stoichiometric coefficient, residence time, reburning temperature and reburning gas - coal heat ratio on NOx emission characteristics was studied in a one-dimensional experimental system. The results showed that the longer residence time of flue gas in reburning zone of furnace will get lower NOx emission, there exists an optimum residence time of flue gas in reburning zone, the optimum residence time is around 0.8s. There also exists an optimum stoichiometric ratio of air in reburning zone of furnace, the value of that is around 1.0. The removing rate of NOx increases with both increasing feeding rate of reburning gas and increasing reburning temperature. The gas reburning technology has been successfully used during reforming an stoker boiler with the capacity of 75t/h, the NOx removing efficiency was over than 50%.