The Industry Challenge:
Pressure transients can damage complex flow systems by mechanisms such as hydraulic hammer and cavitation. These transient conditions can occur during normal operation of the system or during unplanned, emergency shut down events.
Comprehensive models of the fluid rheology, as well as dynamic analyses of pressure wave propagation, are required to understand the conditions that lead to transient events and how the resulting event could impact the performance and integrity of the flow system.
In cases where significant heat loss or gain occurs in the flow system, phase changes in the fluid or changes in the solubility of gases in a liquid could result in the creation of gas and liquid phases that further complicate the system’s behaviour.
This detailed analysis of the flow system is required to select and implement protective equipment such as accumulators and check valves to minimize the impact of transient conditions.
This equipment selection process must further consider ambient operating temperatures which can affect the rate of activation or the durability of components of protective equipment such as elastomeric seals and bladders that become brittle at low temperatures.
How We Help:
C-FER develops models of complex flow systems to understand the steady‑state and transient conditions that can occur. This includes evaluating conditions during controlled startup and shutdown operations, normal operation and during unplanned and emergency shutdown conditions.
For preliminary analyses and simple flow cases, spreadsheet-based analytical models are used to develop a basic understanding of the system and to identify potential conditions where more detailed analyses are required.
For the detailed analyses, a Computational Fluid Dynamics (CFD) approach is taken. In some cases, the effects of pressure transients on the structural integrity of flow system are also assessed using Finite Element Analysis (FEA). The results of the CFD are often verified with lab tests in a custom flow loop or with specialized instrumentation installed in the field.
The analysis of pressure transients provide the client with the information required to troubleshoot operational problems and to select, implement and monitor the performance of pressure and flow control devices.