Quasi two-dimensional mathematical model of the thermal and hydraulic regimes of the tube gas heater

Purpose. Currently, there are long line of unsolved tasks of increase the reliability of the tube gas heaters (TGH). The cause of various defects in TGH is overheating of the surface of heater. As a result the strain and burnout walls is appeared. These processes can be in the linear part of the flame tube from the high temperature gas inside the pipe. The overheating can be arised during starting too. The temperature can reach the maximum value in a short term. The relatively thin walls of the tube are heated fast and unevenly. According to the experimental researches of TGH the temperature have a large fluctuant of temperature along the perimeter of the outer surface of the heater. Is proposed to take into account the factor of influence of the temperature distribution in the angular coordinate on the surface of the heater for increase of accuracy of mathematical modeling of tube gas heaters. Methodology. This work is devoted to mathematical modelling of the thermal and hydraulic regimes in tube gas heater. It is offered the beginning and main parts of the heater do not have a thermal insulation and heat flux is transmitted through the pipe wall into the surrounding airspace. The well-known mathematical model of the parts depends on the only coordinate longitudinal position along the heater and consists of two groups of equations such as heat transfer and motion. Is proposed to take into account the dependence the surface temperature of the heater not only from the linear coordinate but also from the angular coordinate for getting quasi two-dimensional mathematical model of thermal and hydraulic regimes TGH. Findings. It was developed a quasi two-dimensional mathematical model of the hydraulic and thermal regimes of gas tube heater. There are a set of ordinary differential equations. The parameters of regimes depend on both the linear and partly on the angular coordinate. According to the problem can solve by direct calculation of the parameters of the heater by numerical integration. The model is based on the equations of preservation of mass, movement and energy also on heat balance. The two dimensional stationary thermal and hydraulic regimes was calculated. Accuracy of data of a two dimensional mathematical model of gas tube heater is proved. It is based on experimental researches of a mathematical model of the tube gas heater. Originality. The quasi two- dimensional mathematical model TGH is constructed. It was based on experimental researches of temperature distribution along the perimeter of the tube gas heater in dependence on the projecting and regimes characteristics. Practical value. Using of the models for calculation results will help to improve the efficiency of design decisions and the quality of the functioning of the tube gas heater. That model will allow the investigate of TGH.