Pressurized oxy-fuel combustion is a next-generation and low-cost carbon capture technology with industrial application potential. This work presents an innovative research explorationdcoupling coal pressurized fluidized bed oxy-fuel combustion technology with energy utilization of poultry manure as a renewable and carbon-neutral fuel, in order to capture CO2 and solve the problem of poultry manure treatment simultaneously. In this study, a stable co-combustion of coal and chicken manure in a laboratory-scale pressurized fluidized bed under typical oxy-fuel condition (30%O2/70%CO2, i.e., Oxy-30) is achieved. The key parameters including the combustion pressure (0.1e0.5 MPa) and chicken-manure proportion (0% to 100%) and their impacts on fundamental combustion efficiency, carbon conversion, nitrogen and sulfur pollutant emissions, and residue ash characteristics have been investigated. The result show that pressurization favors an increase in the CO2 enrichment concentration and fluidized bed combustion efficiency. During co-combustion under 0.1 and 0.3 MPa, the CO2 concentration in the flue gas is the highest when the chicken manure blending ratio (Mpm) is 25%. Although the NO emissions fluctuate and even increase as Mpm increases, the co-combustion of coal and chicken manure exhibits a synergistic effect in reducing NO conversion rate (XNO). The effect of pressurization on reducing NO emission is significant, XNO at Mpm 1/4 25% decreasing from 15% to 5% as the pressure (P) increases from 0.1 to 0.5 MPa. As P increases from 0.1 to 0.5 MPa and Mpm increases from 0% to 50%, the SO2 emissions and conversion rates decrease. The self-desulfurization process plays an important role in the reduction of SO2 emissions during pressurized oxy-fuel co-combustion. The aim of this work is to advance the development and application of pressurized fluidized bed oxy-fuel co-combustion technology and promote a circular bioeconomy and carbon-free waste management for biomass derived from livestock manure. (c) 2025 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Ultrasonic impedance matching has a wide range of applications in the fields of nondestructive testing and ultrasonic imaging.In this paper,a piezoelectric shunt-based acoustic impedance tunable ultrasonic matching layer is proposed,which consists of a piezoelectric disc with a shunt circuit,and the effective acoustic impedance of the matching layer can be controlled in real time by adjusting the parameters of the shunt circuit.The theoretical results show that the acoustic impedance adjustable ultrasonic matching layer is capable of adjusting the impedance in the range of 1.5～20 MRayl compared with the conventional non-adjustable ultrasonic matching layer.Numerical calculations and simulation analyses also verified the impedance matching effect of the structure,and the transmittance was greater than 90%.Test samples of the acoustic impedance matching structure were fabricated,and the acoustic impedance matching effect of the structure was experimentally verified.
Lamb waves are widely used in non-destructive testing and structural health monitoring due to their advantages of long propagation distance,low attenuation,and high sensitivity to material defects and properties.Phase velocity,as one of the fundamental characteristics of Lamb waves,can be utilized for defect detection,material property estimation,and dispersion evaluation.Most existing phase velocity dis-persion reconstruction methods require the deployment of multiple sensor arrays,which are costly and complex to arrange.This paper proposes a hybrid method based on spectrum decomposition and phase spectrum enhancement,which reconstructs the phase velocity dispersion curves of Lamb waves using only two adjacent sensors.The proposed method was validated through simulations on both aluminum and CFRP plates,and further verified experimentally on CFRP plates.The results were compared with theo-retical values obtained from the semi-analytical finite element method.The findings demonstrate that the phase velocity dispersion curves of both the A0 and S0 modes of Lamb waves were successfully recon-structed,with a consistency rate of over 90%compared to the theoretical values.This method not only simplifies the measurement process but also enhances the accuracy and stability of dispersion curve recon-struction,providing a new technical approach for non-destructive testing and structural health monitoring.
Pulse eddy current testing(PECT)technology can be used for the detection of surface defects,but the outer jacket pipe and the cavity between the jacket pipe and the reactor seriously affect the detection accuracy and signal characterization.Thus,this paper proposes a signal processing algorithm based on coordinate transformation.Firstly,an analytical model of PECT for tubular reactors is established,and the expression of the detection signal is obtained.Then,a signal processing method based on coordinate transformation is proposed,and the correlation curves of the defective signal and the non-defective signal are obtained.Moreover,the slope and intercept of the correlation curve have a linear relationship with the degree of damage of the reactor.Finally,the influence of the jacket pipe on the quantitative assessment of reactor defects is analyzed.Results show that the slope and intercept can still achieve quantitative assessment when the jacket pipe has defects.This paper can provide methods and technical support for the detection of tubular reactors.
