This article provides possibilities for minimising the emissions from eight types of biomass combustion boilers given by virtue of continuous emission measurement. The measurements were carried out on various types of one‐ or two‐stage combustion devices. In all investigated modes of combustor operation, the concentration of nitrogen oxides in the whole cycle of fuel combustion was without marked deviations and far lower than the emission limit of 650 mg/mn3. Concentrations of carbon monoxide (CO) and total organic carbon (TOC) are extremely variable at some operating schedules of combustion boilers. The variability of these concentrations indicates that there are unstable aerodynamic conditions in the combustion device. The causes of this aerodynamic instability have been studied. The mode with stable aerodynamic conditions, for which emission concentrations of CO and TOC are relatively stable, has been determined.
Part of the book: Developments in Combustion Technology
A two-dimensional mathematical model has been created, solved, and verified for the transient nonlinear heat conduction in logs during their thawing in an air environment. For the numerical solution of the model, an explicit form of the finite-difference method in the computing medium of Visual FORTRAN Professional has been used. The chapter presents solutions of the model and its validation towards own experimental studies. During the validation of the model, the inverse task of the heat transfer has been solved for the determination of the logs’ heat transfer coefficients in radial and longitudinal directions. This task has been solved also in regard to the logs’ surface temperature, which depends on the mentioned coefficients. The results from the experimental and simulative investigation of 2D nonstationary temperature distribution in the longitudinal section of poplar logs with a diameter of 0.24 m, length of 0.48 m, and an initial temperature of approximately –30°C during their many hours thawing in an air environment at room temperature are presented, visualized, and analyzed.
Part of the book: Modeling and Simulation in Engineering