OPTIMIZATION OF THE DESIGN OF HEAT EXCHANGERS

Abstract

The intensification of heat transfer is always given great attention to any industry and technology. A promising direction is the use of heat transfer surfaces with a large area, that is, developed, which is achieved by fining the primary surface. When using pneumatic devices, one of the ways to reduce the flow of compressed air is to preheat it in a heat exchanger.The work has developed a methodology for determining the optimal design of a compressed air heater by such a parameter as the total length of the finned tubes. In order to rationally set up an experiment to study the process of constructing the optimal design of a heat exchanger using finned tubes and to determine the stationary area in the face of changing basic factors, a second-order central compositional plan was used.The obtained optimization equation in a rather simple form allows us to analyze the influence of the main parameters on finding the minimum value of the pipe length at a predetermined value of such factors as the number of rows of pipes transverse to the flow and the length of one pipe. According to the Fisher criterion equation of the model is adequate to the true dependence with a confidence probability of 95 %. Analyzing the obtained equation, it is determined that the greatest influence on the total length of the heat exchanger tubes has the number of their arrangement transverse to the heat carrier flow. The effect of the length of one tube across the air flow is of secondary importance. Achieving a reduction in the total length of the tubes used can be by decreasing their number transverse to the flow and reducing the length of one tube.The above technique can be used to optimize any type of heat exchange equipment using developed heat transfer surfaces.