Numerical Simulation Of Flow And Convective Heat Transfer In A Spiral Corrugated Pipe With Field Synergy Theory

Heat transfer enhancement is more and more used in various heat exchange equipment, in order to improve the efficiency of heat transfer and save energy. For the movement of the fluid in the spiral corrugated pipe, the flow and heat transfer in the pipe are different due to the influence of the helical groove structure comparing to smooth pipes.In this paper, based on the FLUENT software, flow and heat transfer of water in the pipe under the different pressures and super-critical pressure was investigated by numerical simulation. Contrast and analysis of the considered viscous correction for correlations and standard k-ε turbulence model and RNG k-ε turbulence model numerical simulation results were performed. From simulations, the RNG k-ε turbulence model is choose to use for numerical simulation.For flow of single phase water at the different pressures, comparing a spiral corrugated pipe with smooth circular pipe, the results show that spiral corrugated pipe has enhanced heat transfer, the effects of inlet velocity、inlet temperature and the structural parameters of spirally corrugated pipe on the radial velocity, temperature and turbulent kinetic energy and turbulent dissipation rate were studied. The effect of heat transfer enhancement is evaluated by using the theory of PEC(Performance Evaluation Criteria), entropy production, heat dissipation and field synergy. Simulated results indicated that heat transfer of all spiral corrugated pipe used in the paper is enhanced the 1.5-2.7 folds and friction pressure increased 1.3-4.5 times, The PEC of all spirally corrugated pipe used were greater than 1. The synergy angle, entropy generation, the entransy dissipation can predict the influence of structure parameters on heat transfer.Numerical simulation of the flow of water near the critical temperature is carried out under the supercritical pressure by means of k-ω SST turbulence model, comparative analysis of the spiral corrugated pipe and smooth circular pipe, the distribution of velocity, temperature, turbulence intensity, turbulence dissipation rate in the radial direction was studied. It is showed that in the pseudo critical temperature zone,the velocity is low at the center of the helical corrugated pipe and increases towards the wall. When approaching to the wall, the profiles of velocity fall down.