LOW PRESSURE PART OF STEAM TURBINE Russian patent published in 2014 - IPC F01D25/30 

FIELD: power engineering.

SUBSTANCE: invention relates to power engineering. A low pressure part of a steam turbine, comprising a control element at the inlet, a group of steps with intermediate chambers and an exhaust nozzle connected to a condenser separated by a piping system into inlet and outlet volumes, at the same time the outlet volume of the condenser is connected to the intermediate chamber, for instance, in front of the last step, by means of a relief pipe with a valve. The proposed technical solution is based on a feature of operation of a low pressure last step at low flow rates of steam, when its impeller does not produce capacity, but receives it from a rotor, spending it for pumping steam towards exhaust. In case of such "compressor" mode of operation the pressure upstream the last step is lower than in the condenser. It makes it possible to send steam into the chamber upstream the last step, which has been cooled by the piping system of the condenser as it leaks from the inlet volume into the outlet volume.

EFFECT: invention makes it possible to increase reliability and cost effectiveness of a steam turbine at low steam flow rates via a group of steps of a low pressure part due to the reduction of ventilation heating of a flow path and elimination of its consequences without use of cooling injections of moisture that intensify erosion, and without increasing the flow of working steam, which reduces release of heat and electric energy.

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