(31a) Transient Flow Analysis in LNG Regasification Terminal Design Safety

As US energy demand rises and domestic energy production remains relatively flat, liquefied natural gas (LNG) is gaining importance as an economically favorable energy source. As a result, many new LNG Regasification Terminals will be built in the US.

The design of the regasification terminal must provide reliable and safe operation, both to ensure a consistent supply of energy to consumers and to minimize the Terminal impact on the surroundings. The Terminal's safety systems typically include fire and gas release monitoring. The final element of the safety system includes emergency shutdown valves (ESDVs) installed throughout the Terminal, to isolate inventory, thereby preventing intensification and escalation of a possible event. To achieve the goal of safe operation, the Terminal's safety system must be analyzed to balance rapid detection and isolation against the effects of transient flow (i.e. water hammer) which can produce pressure rises in process piping of up to five times normal operating conditions.

This paper discusses the areas of the Terminal where transient flow may be expected, outlines transient flow analysis methodology and provides recommendations for minimizing the safety and risks associated with transient flow.