Authors: Xiaowei Zhai; Hui Ge; Dariusz Obracaj
Addresses: School of Safety Science and Engineering, Xi'an University of Science and Technology, 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, China ' School of Safety Science and Engineering, Xi'an University of Science and Technology, 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, China ' Faculty of Mining and Geoengineering, AGH University of Science and Technology, Cracow, PL-30059, Poland
Abstract: An experimental platform was used to evaluate the cooling characteristics of liquid CO2 on coal by changing the mass flow rate and the diameter of injection nozzle. The results show that coal temperature was affected by the phase transition of liquid CO2. Two cooling regions were formed in the vertical sections which would disseminate and finally overlap. In the horizontal sections, the cold volume was reduced from injection centre to the two sides. The functions of furthest cooling influence for both different injection nozzles and different mass flow rates correspond to different nonlinear logarithmic functions. Changing the diameter of injection nozzle had a more promoting effect on cooling range than changing the mass flow rate of liquid CO2. Moreover, parameter K was introduced to estimate the cooled coal volume. The above results could provide a guideline for onsite coal fire prevention and liquid CO2 cooling. [Received: August 10, 2019; Accepted: March 7, 2020]
Keywords: spontaneous coal combustion; SCC; liquid CO2 injection; cooling phenomena; phase transition; cooling influence; cooling parameter.
International Journal of Oil, Gas and Coal Technology, 2021 Vol.27 No.1, pp.54 - 77
Received: 10 Aug 2019
Accepted: 07 Mar 2020
Published online: 30 Apr 2021 *