Speakers
Description
The accuracy of correlations of colburn(j) and friction(f) factor has important effect on the accuracy of simulation results in the dynamic simulation of large scale cryogenic helium systems. However，air was commonly used as heat transfer medium to derive most correlations available in the literatures and experimental results. In order to study the heat transfer and pressure drop characteristics of the offset strip-fin heat exchanger in helium systems, the steady-state three-dimensional numerical models were built. Orthogonal arrangement was adapted to reduce the numbers of simulation. Re, fin length, fin height, fin space, fin thickness were chosen as the parameters in the orthogonal simulation. Through numerical analysis, the j and f factor correlations were developed under different Reynolds (Re<800), which can predict 90% simulation data within ±20% deviation. These results were compared with the existing results obtained by air to find the influence of different fluid medium. The general correlations of j and f presented here probably provides a selection in dynamic simulation of heat exchangers.