General Electric Company

William H Boardman

Emil Donald Jarczynski

Christopher Anthony Kaminski

James Michael Fogarty

Alexander Gabriel Beckford

Robert Gerald Hamilton

Rebecca Ann Nold

A cooling gas ventilation circuit is provided for an end winding of a rotary machine having a rotor of the type having a plurality of radial slots and a plurality of coils respectively seated in the radial slots, the coils extending beyond a pole face of the rotor to form the end winding. The ventilation circuit is composed of first and second cooling gas passages, respectively defined in at least one turn of each coil of the end winding. Each first cooling gas passage extends from an inlet port in communication with a cavity on one longitudinal side of the turn to an exit port defined on the other longitudinal side of the turn. Each second cooling gas passage extends from an inlet port in communication with the cavity on the one longitudinal side of the turn to an outlet in the form of a radial chimney defined through a plurality of the turns of the coil within the respective radial slot. In the presently preferred embodiment, the second passage is longitudinally offset in the coil structure with respect to the first cooling passage, so that they serve to cool respective portions of the coil. The passages may be but are not necessarily defined in the same turn of their respective coil.

Cooling ventilation circuit for rotor end winding and slot end region cooling

A rotating electrical machine with a reverse flow ventilation system is constructed with one or more discharge ducts at the center of the stator core to reduce the air gap pressure and promote more uniform cooling. In a second embodiment, discharge ducts are provided axially displaced from the center line of the core. In another embodiment, end region cooling of the conductor bars is enhanced by a series-parallel flow path constructed with the use of baffles and an apertured plate. In a final embodiment, both stator core center discharge ducts and series-parallel flow end region cooling are incorporated in the same machine.

Reverse flow ventilation system with stator core center discharge duct

In a ventilated cooling system for a generator, the cooling ducts in the stator are arranged to control the flow of cooling gases through the stator. The ducts in the stator extend radially and direct cooling gases from the outer periphery of the stator to its inner cylindrical surface. Cooling gases flow radially inward through these stator ducts, extract heat out of the stator and exit from the stator ducts into an annular air gap between the stator and rotor. A fan on the rotor draws the heated air out from the air gap and causes more cooling gas to be drawn into the stator. The cooling ducts in the stator are spaced and sized to optimally distribute the flow of cooling gases through the stator by equalizing the pressure drops between the stator outer plenum and the entrance to the rotor exhaust fans. For example, the stator ducts may be spaced close together at the center of the stator and farther apart near the ends of the stator to provide balanced cooling flows and uniform temperatures. Similarly, the cross-sectional area of the cooling ducts at the center of the stator may be greater than that of the ducts near the ends of the stator. By arranging the spacing and area of the stator ducts along the length of the stator, the volume of cooling gases and the required pressure head are reduced and minimized. In addition, the volume of cooling gases may be directed to those sections of the stator that most require cooling.

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Burnt Hills, NY, United States of America

William H Boardman