Investigation of the Effect of Flow Rate on Fluid Heat Transfer in Counter-Flow Helical Heat Exchanger Using CFD Method
Keywords:
Simulation, Heat Exchanger with wire insert, Turbulent Flow, Single-Phase flow, Helical Heat TransferAbstract
Heat exchangers are generally used in the process of heat transfer between two
different fluids separated from each other by a solid wall in order to save time and
reduce expenses. Fluids behavior change by adding a wire-insert in its path. To
investigate heat transfer parameters, we need to simulate the whole system. In this
study, heat transfer of counter-flow helical double pipe heat exchanger was modelled
by using Computational Fluid Dynamics (CFD) in "Ansys CFX". The cold and hot fluids
temperature were in the ranges of 10-20C° and 30-50C° respectively. The Reynolds
number of flows were in the range of 4×103 to 42×103 and the process was single
phase. The model was eventually evaluated by experimental data after simulation. The
results indicated that the model was able to interpret the experimental results with
correlation coefficients of 0.98 and 0.97 for hot and cold streams respectively.
Furthermore, the wire-insert installed to the cold flow path caused more fluid
turbulence and increased the temperature difference of the cold fluid inlet and outlet
proportional to the hot fluid.