Heat transfer in the furnaces of boiler units with asymmetry - paradigma-2

Based on the consideration of five schemes of gas flows in the furnaces of boiler units (BU) - frontal, counter, counter-shifted, tangential and hearth, the paper analyses the first three used on BU with a prismatic furnace shape. When the burner devices are located on the front and rear walls, processes with the shape of the initial relative temperature at x = 0 are considered constant and variable. To satisfy the correctness of the requirements of the initial conditions, first, a constant temperature equal to the average over the channel cross section at x = 0 is considered, then, to determine the temperature of the fence tw, the average radiative heat flux in the direction of the horizontal coordinate is determined. The temperature jump is defined as the difference between the radiation temperatures of the gas flow and the enclosure. The heat balance equation is reduced to the canonical form of a linear two-parameter differential equation, which is studied at constant and variable temperatures over the channel cross section. This equation is solved by refining the integration constants, and the resulting solution allows us to determine the Nusselt number as a function of its arguments.