POWER UNIT Russian patent published in 2011 - IPC F04D29/58 F04D29/06 G21D1/04 

FIELD: machine building.

SUBSTANCE: water is supplied to system of shut off water from pressure part of first circuit to ensure normal operation of unit. Relief device 14 opens only at pressure drop occurring when it exceeds pressure drop with closed device 14 of shut down main circulation pump aggregate - MCPA - upon end of its running out while all rest MCPA of unit operate normally. Cooler 6 of a cooling and lubrication system of bearing 4 is positioned over the bearing thus ensuring stable circulation of water both due to natural convection sufficient for withdrawal of heat from the zone of bearing 4 at fixed shaft 1 and at cooling water with cooler 6 when water is withdrawn from the cooling and lubricant system of bearing 4 to the system of shut off water of the operating MCPA. Shut-off accessories 12 on the pipeline of leakage draining from the system of shut-off water operate only with shut down of the MCPA upon end of the latter running out and when water from the pressure section of the first circuit is not supplied to the system of shut-off water.

EFFECT: prevention of overheat of packing unit in operating main circulation pump aggregate and cooling and lubrication system of bearing in idle mode of main circulation pump unit in hot reserve, which increases reliability of power unit.