Experimental and numerical study on gas-solid two-phase flow through regulating valve of pulverized coal flow

Regulating valve of pulverized coal flow is an important gas-solid two-phase valve in the pulverized coal gasification process. Flow characteristics of gas-solid two-phase flow are studied by experimental and numerical approach of computational particle fluid dynamic (CPFD), respectively. The regulation performance of the regulating valve and its influence on the system were investigated. The strong nonlinearity of the relationship between the valve opening and coal flow rate was revealed by experiments and three regions were defined based on the change trend of the coal mass flow rate with the valve opening. Based on the CPFD approach, the process of particles flowing through the regulating valve was observed, and flow parameters including pressure distribution, velocity distribution, and particle volume fraction along the flow channel were analyzed. The model reveals that the presence of the valve introduces strong local inhomogeneities in the gas-solid flow that are studied in order to estimate the regions of the pipe that are mostly affected by the regulating valve. Numerical results indicate that the CPFD method is suitable for the study of pneumatic conveying system with complex flow channels on an industrial scale and can provide a reference for structural design of the regulating valve.