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LOCKING THE ROTOR DURING FORCED COOLING AFTER SHUTDOWN

IP.com Disclosure Number: IPCOM000238548D
Publication Date: 2014-Sep-03
Document File: 3 page(s) / 122K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present invention proposes a technique to accelerate cooling of a combined cycle steam turbine after shutdown. The technique includes locking a rotor during forced cooling process, which in turn restricts rotation of the rotor. Locking of the rotor reduces the risk of rub damage during cooling process.

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LOCKING THE ROTOR DURING FORCED COOLING AFTER SHUTDOWN

BACKGROUND

The present invention relates generally to a combined cycle steam turbine and more particularly to a technique to accelerate cooling of a combined cycle steam turbine after shutdown.

Generally, a cooling medium passes through combined cycle steam turbine steam path to cool a rotor. The rotor remains on turning gear during entire cooling process. However, resultant rotational speed increases risk of rub damage.

A conventional technique includes flow of nitrogen from a nitrogen pump through a single piping header to a flow control station installed under the turbine.

Another conventional technique includes a suction driven air-cooling scheme, which utilizes plant vacuum pumps.

Yet another conventional technique includes introduction of cooling air in a double shell machine between inner and outer shells.

However, the conventional techniques damage the rub during cooling process of the rotor in the combined cycle steam turbine.


It would be desirable to have an efficient technique to reduce rub damage during cooling processes of the rotor in the combined cycle steam turbine.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 depicts motor shafting to lock the rotor during forced cooling process.

DETAILED DESCRIPTION

The present invention proposes a technique to accelerate cooling of a combined cycle steam turbine after shutdown. The technique includes locking a rotor during forced cooling process, which in turn restricts r...