Numerical investigation of the effect of using counter-flow turbulators on pressure change in inner tube heat exchangers; [İç içe borulu isı değiştiricide zıt akışta türbülatör kullanımının basınç değişimine etkisinin sayısal olarak incelenmesi]
No Thumbnail Available
Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Tubular heat exchangers, which are frequently used in industrial processes, are devices that allow two fluids at different temperatures to transfer heat without mixing. By using a turbulator in the flow, effects such as the thinning and breaking of the boundary layer thickness in the flow region, the creation of additional turbulence in the inner circumference of the pipe, the formation of eddy flows in the area of the flow, and the increase in the flow length as a result of the differentiation of the turbulator steps. In this review, turbulators are used in a counter-flow tube heat exchanger. From the area between the two pipes, water at a constant volumetric flow of 50 l / h and a temperature of 298.14 K passes, while air at a temperature of 350 K passes through the inner pipe. The annular type turbulators placed in the inner pipe were investigated numerically in different steps. Pressure drop and friction factor characteristics were investigated for empty and different pitch turbulator models for the Reynolds number range 4000-26000. By using the numerical fluid dynamics program that performs analysis based on finite volume method, the conservation equations are analyzed for three-dimensional conditions in steady regime and for conditions where the flow is turbulent. Numerical analysis was performed according to different flow rates of the internal fluid air and results were obtained. Pressure and velocity contours were created in the heat exchanger according to numerical analysis data. It has been observed that with the addition of a turbulator, the pressure loss is realized for the minimum 100 mm pitch and the highest 25 mm pitch turbulator. It is concluded that the pressure drops increase with the shortening of the step distance in the turbulators, and the pressure drops increase with the increase of the Reynolds number. © 2021, TUBITAK. All rights reserved.