Comparison of heat transfer rates between a straight tube heat exchanger and a helically coiled heat exchanger
The purpose of this study was to determine the relative advantage of using a helically coiled heat exchanger versus a straight tube heat exchanger for heating liquids. The particular difference in this study compared to other similar studies was the boundary conditions for the helical coil. Most studies focus on constant wall temperature or constant heat flux, whereas in this study it was a fluid-to-fluid heat exchanger. Results showed that the heat transfer coefficient was effected by the geometry of the heat exchanger and the temperature of the water bath surrounding the heat exchanger. All tests were performed in the transitional and turbulent regimes.
Performance of metal gasket influenced by the final design of the forming result. Good shape of the gasket will give optimal leakage performance. It is difficult to produce good shape because of the spring back effect. In this study, we investigated the forming process of metal gasket 400MPa-mode for two types of dies which are open dies and closed dies. The finite element method employed to analyze the effect of different types of dies on the final design of the corrugated metal gasket. The simulation shows corrugated metal gasket 400MPa-mode with closed dies result in better final shape than open dies.