It is meaningful to study the issues of CO migration and its concentration distribution in a blind gallery to provide a basis for CO monitoring and calculation of fume-drainage time, which is of a great significance to prevent fume-poisoning accidents and improve efficiency of an excavation cycle. Based on a theoretical analysis of a differential change of CO mass concentration and the CO dispersion model in a fixed site, this paper presents several blasting fume monitoring test experiments, carried out with the test location to the head LP in arrange of 40-140 m. Studies have been done by arranging multiple sensors in the arch cross-section of the blind gallery, located at the Guilaizhuang Gold Mine, Shandong Province, China. The findings indicate that CO concentrations in the axial directions are quadratic functions with the Y and Z coordinate values of the cross-section of the blind gallery in an ascending stage of CO time- -concentration curve, with the maximum CO concentrations in Y = 150 cm and Z = 150 cm. Also, the gradients of CO concentration in the gallery are symmetrical with the Y = 150 cm and Z = 150 cm. In the descending stage of CO time-concentration curve, gradients of CO concentration decrease in lateral sides and increase in the middle, then gradually decrease at last. The rules of CO concentration distribution in the cross-section are that airflow triggers the turbulent change of the CO distribution volume concentration and make the CO volume concentration even gradually in the fixed position of the gallery. Moreover, the CO volume concentrations decrease gradually, as well as volume concentration gradients in the cross-section. The uniformity coefficients of CO concentration with duct airflow velocities of 12.5 m/s, 17.7 m/s and 23.2 m/s reach near 0.9 at 100-140 m from the heading to the monitoring spot. The theoretical model of a one-dimensional migration law of CO basically coincides with the negative exponential decay, which is verified via fitting. The average effective turbulent diffusion coefficient of CO in the blind gallery is approximate to 0.108 m2/s. There are strong linear relationships between CO initial concentration, CO peak concentrations and mass of explosive agent, which indicates that the CO initial concentration and the CO peak concentration can be predicted, based on the given range of the charging mass. The above findings can provide reliable references to the selection, installation of CO sensors and prediction of the fume-drainage time after blasting.

The high temperature and thermal radiation caused by generator fire accidents on the offshore platform lead to the destruction of equipment and facilities and threaten the structural safety of the offshore platform. Based on the background of a crude oil generator fire accident on an offshore platform, KFX software was used to conduct a numerical simulation of the fire process and explore the spatial-temporal variation characteristics of smoke, temperature and heat radiation within the scope of the fire room. The influence ranges of 12.5 kW/m2, 25 kW/m2 and 35 kW/m2 were obtained according to the thermal radiation criterion. Researchers examined the temperature variation and heat flow at the room’s ceiling and floor near the primary steel support. The results show that: 1) The surface temperatures of partial steel supports exceed 550°C, and the heat flux of partial steel supports exceeds 37.5 kW/m2. 2) In the ignition position, the maximum temperature at the ceiling reaches 2299°C when t = 24 s, and the maximum temperature at the flooring reaches 701°C when t = 79 s. The heat radiation flux at the ceiling and flooring both exceeds 25 kW/m2. The maximum temperature of partial crude oil generators can reach 1299°C. 3) The heat radiation flux of partial generators can reach 105 kW/m2, and the heat radiation flux at the adjacent point of partial generators never exceeds 20 kW/m2. The above research results can provide a reference for checking the response time of flame detectors and the strength of the supporting structure.