PURPOSE: To prevent water hammer from occurring in a hydraulic iron tube by providing a flowrate control valve and a release valve in a water channel in a manner that the flowrate control valve opens or closes inversely to the release valve.
CONSTITUTION: Water 1 from a brook constructed with a dam 2 is fed through water channels 3, 4 to a hydraulic turbine 6 to thereby drive the turbine 6. The turbine 6 employs a centrifugal vane wheel (centrifugal pump) having no guide vane to control the flow rate to the turbine 6 via a flowrate control valve 9. A release valve 10 is provided in a bypass channel. The flowrate control valve 9 opens or closes inversely to the release valve 10 to be so controlled that, even if the flow rate of the turbine 6 varies as the load of the turbine 6 is changed, the flow rate in the main channel maintains contant. Accordingly, almost no water hammer occurs in the water channels (hydraulic iron tube) to thereby safely retain the iron tube and equipments.
TAKESHITA KOUJI
MORIMOTO HARUKI
TOUKO YOSHIAKI
