Surge Analysis Insights

Large and Complex Surge Modelling of New Deluge Firewater System

Our latest paper on “Very Large and Complex Surge Modelling of New Deluge Firewater System” provides an in-depth examination of surge analysis for an extensive deluge firewater system. Using the BOSfluids software, the study compares detailed and simplified models derived from 5140 isometric drawings and general arrangement (GA) drawings, respectively.

The detailed model includes a comprehensive representation of the system's geometry, while the simplified model omits certain elements such as pipe bends and elevation, resulting in a less accurate depiction of system pressure drop and hydrostatic pressure. The study found that while simplified models can approximate general trends in flow rate, pressures, and unbalanced forces, they fall short in capturing the precise surge pressures and cavitation effects observed in the detailed model.

Key findings indicate that maximum surge pressures and unbalanced forces were within 10-15% accuracy in the simplified model compared to the detailed one. However, parameters like system pressure drop were significantly underestimated in the simplified model. The analysis also highlights the importance of including detailed geometric data to accurately predict surge pressures due to cavitation, which are highly dependent on local piping geometry and elevation.

The study underscores the necessity for high-fidelity models in complex surge analysis, especially for systems like the deluge firewater system discussed. It concludes with recommendations for surge analysis, emphasizing the balance between computational cost and model accuracy.

For a comprehensive understanding of the methodologies, results, and implications of this research, you can read the full paper here: https://dynaflow.com/wp-content/uploads/2024/07/Modelling-Deluge-Firewater-System.pdf

This detailed study is a valuable resource for professionals involved in the design and analysis of large-scale piping systems, offering critical insights into the complexities of surge modelling.

Designing for Pressure Surges in an LNG Bunkering Line

The LNG bunkering process is integral to the marine fuel industry, providing ships with liquefied natural gas. However, the operation comes with significant risks, particularly related to pressure surges.

Our latest study, "Designing for Pressure Surges in an LNG Bunkering Line," sheds light on the critical aspects of managing these risks using advanced engineering techniques and tools developed by Dynaflow Research Group (DRG).

Transient upset scenarios occur when there is a sudden change in the steady-state flow conditions within the pipeline, such as the quick closure of a valve or an abrupt pump trip. These scenarios can lead to substantial pressure fluctuations, causing potential damage to the piping system. The paper illustrates the severe consequences of such events, including pipe ruptures and the failure of pipe supports, emphasizing the necessity of comprehensive surge analysis.

One of the key highlights of the paper is the application of the Joukowski equation to predict the maximum amplitude of pressure surges. For an LNG bunkering line with specific parameters (flow velocity of 3 m/s, density of 450 kg/m3, and speed of sound of 1400 m/s), the resulting pressure surge can be as high as 19 bar. This theoretical approach is crucial for designing systems that can withstand such forces.

Pressure surges not only cause direct pressure spikes but can also induce vibrations within the piping system. These vibrations, if resonant with the system's natural frequencies, can amplify the stress on the pipes, leading to potential failures. Additionally, the paper addresses the risk of cavitation in elevated sections of the pipeline. Cavitation occurs when the pressure drops below the vapor pressure of LNG, forming vapor pockets that can collapse violently, causing further pressure surges.

To mitigate these risks, the paper outlines several strategies, including the use of emergency shut-down (ESD) valves and the design of appropriate axial restraints to handle unbalanced forces. The study also utilizes advanced simulation tools, specifically the BOSfluids? software, to model various scenarios and predict the system's response to different transient events. For example, the closure duration of valves and the accurate modeling of valve resistance (Cv) are critical in managing the resulting pressure surges effectively.

This paper concludes by highlighting the importance of detailed surge analysis and robust design to ensure the safety and reliability of LNG bunkering lines. The simulations demonstrate that with proper design and adequate safety mechanisms, it is possible to maintain pressures within allowable limits even under extreme conditions.

For those interested in a more comprehensive understanding of the methodologies and results discussed, the full paper is available on the Dynaflow website: https://dynaflow.com/wp-content/uploads/2024/07/Consulting_Surge_LNG-Bunkering-Line.pdf

Don't hesitate to reach out if you need further details regarding our surge analysis services.

Fiberglass Pipe Stress Analysis Webinar

Join us for an exclusive webinar on Fiberglass Pipe Stress Analysis with Edwin Schimmel, Project Engineer at Dynaflow Research Group!

In this session, you will gain a better understanding of:

? Fundamentals of fiberglass piping

? Stress envelope construction

? Practical application in CAESAR II

Perfect for engineers, designers, and professionals working with FRP piping systems. Gain valuable insights to enhance your pipe stress analysis capabilities.

?? Date: 24th of July

?? Duration: 45 minutes

Don't miss this opportunity to learn from industry experts. Register now to secure your spot!

Register here: https://dynaflowresearchgroup.clickmeeting.com/fiberglass-piping-stress-envelope-according-to-iso-14692-using-caesar-ii/register