Liquid Pipeline/Network Design based on Hydraulic Transient Analysis

Summary

For design and operation of liquid pipeline networks such as large cooling water systems, fire fighting water networks, product loading lines, long distance liquid pipelines, etc., water hammer analysis plays an important role to consider transient nature of liquid flows in the pipeline networks. For more than 25 years, TOYO has applied the water hammer analysis to our design and commissioning of liquid pipeline networks and accumulated a lot of experiences to study and overcome water hammer related problems.

TOYO provides water hammer analysis services with our best knowledge and expertise based on the rich practical experiences.

Features

TOYO’s in-house program WATHAM-II which has been extensively applied to our actual pipeline engineering is used for the analysis.

Based on our experiences, TOYO can provide realistic and effective engineering solutions for design or operation of the pipeline to avoid or overcome the water hammer related problems.

Services

Typical upset sources in a liquid service pipeline network which may cause the water hammer problems are pump trip followed by check valve closure and quick operation of control valves. Steep pressure increase and decrease are often generated by such events and the pressure upset quickly propagates over the system along the associated piping. The increasing pressure propagation may cause overpressure problem, while the decreasing pressure propagation may cause vacuum problem and sometimes induces secondary pressure upset due to vapor cavity formation and collapse (vaporization and condensation) at highly elevated portions, dead ends, etc.. In addition, steep pressure upset propagation itself induces impulsive fluid dynamic loads on the piping which may cause serious piping vibrations and damages in pipe supports, valve and equipment casings, etc..

TOYO’s water hammer analysis simulates such complicated transients in the liquid pipeline network in detail and helps to quantitatively evaluate the soundness of its design and operations. If undesirable situations are expected in the system, TOYO can investigate realistic and effective measures to overcome the problems such as pipe support reinforcement, adoption of better performance check valves, adjustment of valve actions, sizing and location optimizations for vacuum breakers or relief devices, optimization of interlock logics, etc., and recommend the best solutions to the customer.

Examples of Water Hammer Analysis

When one of running pumps trips, flow reversal occurs at the tripped pump and the pump discharge check valve automatically closes. The instantaneous closure of the check valve causes steep pressure jump across the check valve and generates shock force to push the check valve. This analysis example demonstrates the dynamic system response study of a pump station under such situation. The fluid flow transients around the pump station are computed by WATHAM-II and the wave shape of the resultant shock force on the check valve is derived from the computation result. The dynamic system response of the structural side to the shock force is computed by the commercial piping analysis code CAESAR-Ⅱ.

Overview of Pumps

Calculation Model

Calculated Result

Calculated Result(Power to the pump and support)