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Experimental investigation of the impact of liquid carbon dioxide injection on temperature in pulverized coal
Author(s) -
Yu Zhijin,
Yang Song,
Wen Hu,
Deng Jun
Publication year - 2020
Publication title -
greenhouse gases: science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.45
H-Index - 32
ISSN - 2152-3878
DOI - 10.1002/ghg.1954
Subject(s) - pulverized coal fired boiler , nozzle , coal , materials science , carbon dioxide , combustion , thermodynamics , mechanics , chemistry , physics , organic chemistry
Using liquid carbon dioxide (LCO 2 ) as a medium for underground coal fires prevention and control, while reducing the emissions of CO 2 , is a promising option for CO 2 utilization worldwide. However, the mechanism of LCO 2 flow with phase transition on coal temperature is still not clear. In this work, an experimental system was designed and fabricated to investigate the phase transition behavior and temperature variation during injecting LCO 2 into pulverized coal and the impact of mass flow rate, nozzle diameter, and injection pressure on cooling effect. The results indicate that when LCO 2 was injected into the pulverized coal, the instantaneous phase change into solid and vapor occurred just after leaving the release port. An intensive heat transfer process occurred because of the throttling effect, flashing effect, and sublimation and thereby formed a cooling area (<−56.6°C), which was the main area of cooling effect and phase transition; as injection time increases, the range of this area increases in the form of logarithmic function. In addition, the cooling area exhibited a strong dependence on the injection conditions, and its correlation with mass flow rate, nozzle diameter, and injection pressure are identified as exponential, logarithmic, and linear relationship by dimensionless analysis, respectively. Meanwhile, an empirical formula was developed for calculating the cooling effect under various injection conditions. In summary, the experiments provided fundamental data and regime for predicting the effect of LCO 2 injection on the temperature of pulverized coal, which can be used to guide the utilization of LCO 2 for coal fires prevention. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.