THE RESEARCH OF THE SPEED AND TEMPERATURE FIELDS IN THE FLOW PASSAGES OF THE EXHAUST HEAT BOILER BY THE NUMERICAL EXPERIMENT METHOD
The paper presents the description and results of the numerical experiment in terms of the mathematical model of the sectional exhaust boiler with bypass line integrated in the general case, carried out in the research version of the software package of the computing hydraulic and gas dynamics FlowVision. The tasks of the computer modeling were the detection of the heat-exchange unit working conditions taking into account possible unevenness of the velocity field on the entrance area and the detection of the effect of this unevenness on the temperature field in the gas duct. The computing experiment comprised several prestages including the receiving of the gas space solid-state model, detected the calculated area scopes, from the geometrical model of the researching exhaust boiler and the determination of the boundary conditions at the initial temperature in the gas duct 60 °C. Modeling of the temperature field was obtained by the method of the cold gas displacement. By the results of the numerical experiment it was found that the unevenness of the velocity distribution of the heat carrier (absolute values) in the exhaust boiler flow areas is slight, excluding the tear-off zone at the entrance of the exit branch, and the kind of change in gas temperature allows coming from grid models with thousands final-extensional elements to engineering calculation models, where heat transfer equations for a dozen of knots are considered. As a result, the information about the gas moving character in the conducts of the described exhaust heat boiler, which can offer the optimization of its construction, and the necessary results (velocity and temperature fields) for designing and verifying the heat-exchange model with low distributed parameters are obtained.