Effectiveness comparison of surge reduction systems and gas accumulators
Emergencies during operation of trunk pipelines often come from surge waves arising as a result of flow rate change. 1 m/s of flow speed deceleration is known to create a surge wave with amplitude of 1 MPa. That is why a lot of pipelines operating with flow speed up to 3.5 m/s are equipped with surge protection systems. The paper studies a comparison of two different protection systems used to reduce effect of surge waves on main pipeline facilities. Reviewed systems are gas accumulators and surge reduction systems. Both types of protection devices are usually installed in the upstream pipeline of pumping station in order to reduce sharp pressure increase in case of pump station shutdown/control valve closure. A closed pipeline section partially filled with rare gas (e.g. nitrogen) and freely connected to the protected pipeline is considered as a gas accumulator. In order to perform a specified research has been implied a method of mathematical modeling of transient flow of incompressible fluid. Each of the compared systems had been set to maintain equal rate of pressure increase, after that doubled volume of required drain tank for surge reduction system and volume of gas accumulator were compared. It is shown that in each case the compared parameters are equal; therefore choice of preferred protection system should be determined by comparison of additional economic indicators.