Heat transfer simulation and thermal efficiency analysis of new vertical heating furnace

Mathematical Model of a Heating Furnace Implemented with Volumetric Fuel Combustion

“…The fuel is fed to the heating furnace with a regenerator (1) via gas nozzles (4). After heating in the regenerator, the combustion air enters working chamber (2) with the heated material (3), through the flue gas ducts (5) which serve as air ducts or smoke windows, depending on the heating stage. The cross-sectional area of the gas nozzles and air ducts, and their number, geometrical shape, and relative positioning ensure such a degree of reagent mixing that the tolerable value of fuel non-combustion in the exhaust section is 0.1% to 5% and is completely absent at the exit B-B.…”

“…According to Equations (2)-(4), α c is calculated as − λ ∂t ∂z x = ±R = ±α c t e f − t sur (5) The calculation diagram, the dividing of the furnace into i elements, and the mass flow rates of the furnace gas circulation are shown in Figure 2. The working space of the heating furnace is divided into parts (zones) i = 2n, in each of which an ideal mixing is assumed.…”

“…The presence and degree of development of local furnace gas circulation zones can change the regime of smoke movement in the furnace over a wide range: from the "short circuit" mode to the development of decompensated mixing, with the return flow of part of the furnace gas mass flow to the initial part of their path (recirculation regime). The intermediate state with small-scale compensated mixing [5] is called displacement with a compensated mixing regime. The occurrence of both regimes of movement in real conditions depends on the energy of the gas flows from the furnace.…”

“…Processes 2020, 8, x FOR PEER REVIEW 5 of 20 of the furnace gas mass flow to the initial part of their path (recirculation regime). The intermediate state with small-scale compensated mixing [5] is called displacement with a compensated mixing regime. The occurrence of both regimes of movement in real conditions depends on the energy of the gas flows from the furnace.…”

“…Thus, every calculation zone has a minimum of three (zones 1, 8, 9, and 16 have four) of the six calculation surfaces defined as boundary surfaces. Such boundary surfaces have 2nd-or 3rd order boundary conditions according to Equations (1)- (5). The other surfaces of the calculation zones are interfaces and are calculated according to Equations (6)- (19).…”