Method and system for use in cooling a joint flange bolt of a rotary machine

Abstract

A method of cooling at least one joint flange bolt used with a rotary machine includes extracting a working fluid having a first temperature that is lower than an operating temperature at a first joint flange bolt hole. The method also includes diverting a first portion of the extracted working fluid into a first supply hole that is in flow communication with a first clearance gap defined between the first joint flange bolt hole and the joint flange bolt. The method further includes exhausting the first portion of extracted working fluid through a first exhaust hole in flow communication with the first clearance gap, such that the first portion of extracted working fluid flows around the exterior surface of the joint flange bolt. Additionally, the method includes routing the first portion of the extracted working fluid into a first conduit in flow communication with the first exhaust hole.

Description

BACKGROUND[0001]The field of the disclosure relates generally to cooling a casing of a rotary machine, and more particularly to a method of cooling a casing joint flange bolt of a rotary machine.[0002]At least some known rotary machines, including some known steam turbines, are housed within a casing that is generally shaped like a horizontal tube, formed by an upper section and a lower section. In at least some such known rotary machine casings, the section and lower sections of the casing are coupled together along a pair of horizontal joints that extend axially along each side of the generally tubular casing. The upper and lower sections of the casing may each include a flange that extends along each joint and that includes aligned bolt holes defined at several locations in each upper and lower flange. Bolts may be installed in these joint flange bolt holes to couple the casing sections together. The bolts may need to maintain a fastening torque at or above a required level to en...

AI Technical Summary

Benefits of technology

The patent describes a method, system, and rotary machine that use a working fluid to cool down certain parts, such as joint flange bolts, to prevent damage during operation. The system includes an extraction bore that extracts the fluid, which is then directed to the bolts to cool them down. The method and system can help improve the lifespan and performance of rotary machines.

Problems solved by technology

The increased temperatures may cause the joint flange bolts to suffer increased “creep relaxation,” that is, a loss of bolt fastening torque over time.

As such, the costs associated with these joint flange bolts may be higher than for other known bolts.

However, because the primary cooling is performed on the joint flange, rather than on the bolts themselves, the benefits of such cooling are limited.

While this method provides cooling directly to each bolt, rather than indirectly through the joint flange, it introduces the manufacturing difficulty of boring holes through hardened bolts.

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