Method and means for starting and stopping once-through high-pressure steam boilers

Claim 1

IN THE METHOD OF STARTING AND OPERATING A HIGHPRESSURE ONCE-THROUGH STEAM BOILER FORMING PART OF A POWER PLANT COMPRISING A MAIN FORST STEAM TURBINE ADAPTED TO BE CONNECTED TO THE STEAM BOILER, A FIRST CONDENSER WITH A CONDENSATE TANK, CONNECTED TO THEEXHAUST OF SAID FIRST STEAM TURBINE, A START-UP SECOND STEAM TURBINE ADAPTED TO BE CONNECTED TO THE STEAM BOILER IN PARALLEL WITH SAID FIRST TURBINE AS REGARDS THE FLOW OF THE STEAM THROUGH THEM, A SECOND MIXING TYPE CONDENSER CONNECTED TO THE OUTLET OF THE SECOND TURBINE, A HYDRAULIC BRAKE DRIVEN BY SAID SECOND TURBINE, THE STEPS OF: CONNECTING THE SECOND TURBINE WITH THE BOILER DURING THE STARTING OF THE BOILER WHILE THE FIRST TURBINE IS AT STANDSTILL AND NOT CONNECTED TO THE BOILER, DISSIPATING THE MECHANICAL OUTPUT OF SAID SECOND TURBINE IN SAID HYDRAULIC BRAKE AS HEAT AND LEADING CONDENSATE FROM SAID CONDENSATE TANK OF SAID FIRST CONDENSER THROUGH THE HYDRAULIC BRAKE TO HEAT SAID CONDENSATE, CONDENSING THE LOW-PRESSURE EXHAUST STEAM ISSUING FROM SAID SECOND TURBINE AT LEAST PARTIALLY IN THE SECOND CONDENSER BY MIXING IT WITH THE HEATED CONDENSATE ISSUING FROM THE HYDRAULIC BRAKE, DISCONNECTING THE SECOND TURBINE FROM THE BOILER WHEN THE STEAM FURNISHED BY THE BOILER HAS REACHED A PREDETERMINED PRESSURE AND TEMPERATURE, AT THE SAME TIME STARTING THE FIRST TURBINE BY CONNECTING IT TO THE BOILER, AND DISCONNECTING THE WATER FLOW FROM THE CONDENSATE TANK OF THE FIRST CONDENSER TO THE HYDRAULIC BRAKE.