(586d) Enhanced Heat Transfer in the Helical Baffled Heat Exchanger with Optimal Design of Flow Stream

The helical baffled heat exchanger is the upgraded shell and tube heat exchanger, except supporting the pipe bundle, the main function of the baffles is to create the flow channel for the shell side fluid. In this paper, the flow stream analyze in the helical baffled heat exchanger were investigated. Compared the stream dividing results in the segmental baffled heat exchanger, the flow stream in the helical baffled heat exchanger was divide into 5 parts, and the factors causes the leakage stream flow F through the axis of heat exchanger was present via analytical calculation. By means of numerical calculation for helical baffled heat exchanger with clearances between tubes and baffled as well as the clearances between baffled and shells, following conclusions are obtained: first, with the increase of Reynolds number, both the ratio of main flow stream B and the ratio of the leakage stream flow F fall; second, as the helical angle raises, the ratio of B and the ratio of F increases and decreases, respectively; third, the correlations for the ratios of all flow streams under different Reynolds numbers and helical angles were present. With the optimal design of flow stream for a heat exchanger in industrial scale, the heat transfer rate increased 32% and the pressure drop dropped 23% respectively.