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The coal/ammonia co-firing technology for thermal power generation is a feasible method to effectively reduce CO 2 emissions. However, the easy formation of NO x is one of the challenges faced by this technology owing to the high nitrogen content in ammonia. This study proposes a novel swirl burner with a scalable dual-channel ammonia pipe, and evaluates the combustion and NO x formation under different extension lengths of the dual-channel ammonia pipe (i.e., 0 m, 0.4 m, 0.8 m, 1.0 m, 1.2 m). The results show that the extension length of the dual-channel ammonia pipe significantly affects the flow, combustion, and NO x formation. When the extension length of the dual-channel ammonia pipe is above 0.8 m, the ammonia stream can completely penetrate the internal recirculation zone into the high CO environment, which contributes to promoting the ammonia pyrolysis and inhibiting the ammonia oxidation to form NO x. NO x emissions significantly decrease from 846 ppm to 146 ppm as the extension length of the dual-channel ammonia pipe from 0 m to 0.8 m, but change slightly as further increases from 0.8 m to 1.2 m. The carbon content in fly ash decreases from 4.53% to 3.40% as the extension length of the dual-channel ammonia pipe increases from 0 m to 1.0 m. Still, it increases from 3.40% to 3.70% as the extension length of the dual-channel ammonia pipe rises to 1.2 m. Overall, it is reasonable to set the extension length of the dual-channel ammonia pipe at 1.0 m in this studied condition, which can obtain low NO x and low carbon content in fly ash. [Display omitted] • A novel swirl burner with a scalable dual-channel NH 3 pipe is proposed. • Effect of NH 3 pipe extension length on combustion and NO x formation is investigated. • NH 3 pipe extension length significantly affects flow, combustion, and NO x formation. • 1.0 m for NH 3 pipe extension length is reasonable with good performance. [ABSTRACT FROM AUTHOR]

[Objective] As an important type of coarse-grained sedimentary system and oil and gas reservoir in faulted basins, fan delta and slump fan complex deposition has been the hot topic of research on lacustrine sedimentary and reservoir formation, such as distribution area, evolution period and accumulation model. [Methods] Based on high resolution 3D seismic and drilling and logging data in the A Sag of Melut Basin in central Africa region, the sedimentary characteristics and evolution of fan delta-slump fan complex are studied by using core observation, sequence division, seismic reflection characteristics and seismic attribute analysis. [Results and Conclusions] The results showed that the types of sedimentary facies of fan in the study area included fan delta and slump fan caused by gravity flow, slump fan had two types of morphology characteristic, the first one was line source slump fan controlled by slope break, the second one was multistage slump fan with single point source controlled by steep topographic slope. Combined with seismic profiles and well logging features, five periods of fans were recognized in the Cretaceous study section. The single-stage fan all had the characteristics of retrogradation, the vertical evolution of multiple periods of fans was characterized by "first progradation and later retrogradation" . The fan distribution was the largest at the end of Renk Formation deposition in the Lower Cretaceous, reaching 148 km². However, the fan evolution was mainly influenced by tectonic activity, palaeogeomorphology, provenance supply, and base-level cycle. The fan distribution was larger in the period of strong tectonic activity, abundant provenance supply and large short-axis tectonic uplift, and the slump fan was most developed in the early period of relative base-level rising cycle and decreasing cycle. A new understanding of the sedimentary pattern transformation occurred in the Early Cretaceous and Late Cretaceous in the A Sag was put forward. The exploration potential of the fan delta and slump fan complex deposition in the faulted depression is clarified, which guided the exploration deployment. [ABSTRACT FROM AUTHOR]

During the pneumatic conveyance of biomass in a coal-fired power station boiler, biomass particles have cylindrical shapes with different aspect ratios. They move through the fluid at any angle and rotate strongly. However, highly accurate and general models of the drag, lift, and torque coefficients (CD, CL, and CT) for biomass particles in a wide range of aspect ratios, especially the CT model and the high aspect ratios, are currently lacking. This paper presents detailed direct numerical simulations of the flow around cylindrical cylinders with varying aspect ratios (6 ≤ AR ≤ 22), Reynolds numbers (100 ≤ Re ≤ 2000), and angles of incidence (0° ≤ θ ≤ 90°). The simulation was conducted using the OpenFOAM solver with the body-fitted mesh method. The flow characteristics and force coefficients of cylindrical particles with different AR were systematically analyzed. New functional correlations between CD, CL, and CT and AR, Re, and θ values were established. The mean squared errors for CD, CL, and CT were 8.8 × 10–2, 2.4 × 10–2, and 4.7 × 10–2, with average relative errors of 5.8%, 3.5%, and 8.17%, respectively. A comparison of the results with other experimental and simulation data in previous literatures showed that the new CD and CL models have considerable higher predictive ability. The generality of the new CD model expanding to low ARs of 1.5 and 3 is verified finally. The new force and torque models are expected to improve the accuracy of Eulerian–Lagrangian simulations of various cylindrical particle-laden flows in the utility of biomass energy. [ABSTRACT FROM AUTHOR]