Performance Study Of Flow And Heat Transfer In Shell-Side Of Shell-and-Tube Heat Exchanger With Helical Baffles

As universal heat transfer equipments, heat exchangers are widely applied in various sectors, such as chemical industry, power generation, environmental protection, food processing. The shell-and-tube heat exchanger (STHX) has been the most comprehensive heat exchanger, owing to its low production cost, simple structure, strong adaptability, work reliability. Considering its significance in industrial field, the improvement of its performance makes much difference to China’s sustainable development.In this paper, method intergrading numerical simulation and experiment is applied to study the performance of STHX with helical baffles. Studies are mainly focusing on following aspects:Shell-side flow domain model of STHXs with continuous and non-continuous helical baffles were established by the application of3-D modeling software Pro/E. Viscosity which depends on temperature of the working fluid was considered and boundary condition is properly defined.RNG k-ε turbulence model and mesh adaptive technology is applied to numerical simulate shell-side flow domain. The calculation method of the shell-side characteristic velocity and Reynolds number is given. In order to describe the distribution of local flow resistance, mechanical energy dissipation rate is adopted.The numerical simulation results of STHXs with continuous helical baffles show the effects of the central tube on axial distribution of heat transfer and flow resistance, distribution of shell side flow field, circumferential and axial velocity component, local flow resistance, and local quantity of heat transfer.The numerical simulation results of STHXs with non-continuous helical baffles show the effects of different arrangements of helical baffles (continuous overlapped, edge overlapped, staggered overlapped, double helical baffles) on distribution of shell-side physical quantity, as well as the flow and heat transfer properties.The experimental apparatus of STHXs with helical baffles was set up. The flow and heat transfer properties were investigated experimentally. The results present that shell-side comprehensive performance of STHXs with helical baffles is superior to that of STHXs with segmental baffles, which validates the reliability of numerical method.