MR-HM 156 Water Hammer and Surge Chamber Vocational Training Equipment Fluids Engineering Experiment Equipment Description • visualisation of water hammer • operation of a surge chamber • determining the sound velocity inwater • GUNT software for displaying thewater hammer and oscillations In structures such as hydroelectricpower plants, or in systems for supplying water, changes in flow rate result inpressure fluctuations. For example during startup and shutdown of hydraulicmachines or by opening and closing shutoff elements. There is a distinction to bemade between rapid pressure changesthat propagate with the sound velocity(water hammer) and slow pressurechanges caused by mass oscillations. Pipeline systems use air vessels orsurge chambers to dampen water hammer and mass oscillations. MR-HM 156 is used to generate and visualise water hammer in pipes and todemonstrate how a surge chamberworks. The trainer contains a pipe section with a ball valve and a surge chamber and a second pipe section with asolenoid valve. In the first experiment a water hammeris produced by rapidly closing the ballvalve. The sudden deceleration of thewater mass releases kinetic energy,which is converted into potential energyin the surge chamber. The resultingpressure oscillations are measured by apressure sensor behind the surgechamber and displayed in the softwareas a pressure curve. The oscillation canalso be seen as pendulum movement ofthe water level in the surge chamber. In the second experiment a rapid closingof the solenoid valve in the second pipesection produces a strong water hammer. The water‘s kinetic energy is converted into pressure energy. The waterhammer and the subsequent oscillationsare detected by two pressure sensors inthe pipe section and displayed in thesoftware as a pressure curve. The water is supplied and the flow ratemeasured by the supply unit. Learning objectives/experiments • demonstrating water hammer in pipes • determining the sound velocity in water • understanding how a surge chamberworks • natural frequency in the surge chamber Specification [1] functioning of a surge chamber [2] pipe section with ball valve and surge chamber [3] surge chamber designed as transparent PMMAtank [4] pressure sensor behind the water chamber formeasuring the pressure wave [5] pipe section with solenoid valve and two pressuresensors for measuring water hammer [6] volumetric flow measurement via supply unit [7] representation of the pressure curves with GUNTsoftware [8] GUNT software for data acquisition via USB underWindows 7, 8.1, 10 Technical data Pipe section for pressure oscillations • copper • length: 5875mm, inner diameter: 26mm • ball valve • surge chamber, PMMA Height: 825mm, inner diameter: 50mm Pipe section for water hammer • copper • length: 5875mm, inner diameter: 26mm • distance between sensors: 3000mm • solenoid valve, closing time: 20…30ms Tank: 50L Supply unit Pump • power consumption: 550W • max. flow rate: 230L/min • max. head: 11m Tank: 1x 180L, 1x 40L Measuring ranges • pressure (pipe section): 2x 0…16bar abs. • pressure (surge chamber): 0…0,3bar 230V, 50Hz, 1 phase 230V, 60Hz, 1 phase; 120V, 60Hz, 1 phase UL/CSA optional LxWxH: 6800x800x2050mm (total) Weight: approx.155kg Required for operation PC with Windows Scope of delivery 1 trainer with supply unit 1 GUNT software CD + USB cable 1 set of instructional material
