Failure Analysis of a High-Pressure Natural Gas Heat Exchanger and its Modified Design

Abstract

The beauty of numerical simulations is its ability to reveal the physics or nature of practical engineering problems in detail, and then, to identify adequate solutions. In this chapter, an excellent example is demonstrated. The rupture of a heavy-duty, high-pressure natural gas heat exchanger is numerically investigated, and the importance of gravity effect is identified, which is often considered as a trivial factor. For the original design, the natural convection in the flow field of the heat exchanger is comparable with the forced convection at the designed operating conditions. These two convections are perpendicular and compete with each other, the flow field is highly unsteady, and hightemperature natural gas is trapped in the upper portion of the vessel, which causes the damage of the exchanger. By vertically mounting the exchanger assembly and locating the outlet pipe on top of the exchanger, the flow parameters become rather uniform at each vertical cross section and the wall temperature of the heat exchanger remains more or less the same as the heated natural gas. The proposed design has been successfully used up to now.