The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 2000
Filed:
Feb. 17, 1999
Naoki Hagi, Takasago, JP;
Mitsubishi Heavy Industries, Ltd., Tokyo, JP;
Abstract
A clearance control system for a turbine seal optimizes a clearance by controlling the change in the clearance during a run due to a thermal elongation by cooling the sealing air. The air from a compressor is cooled by a cooler 12 and is guided via an outer shroud 22 and a tube 28 in a stationary blade 21 into a cavity 26 in an inner shroud 23. The air flows through a space 34 from a seal portion 36 to the outside and through a seal ring 25 and a space 35 from a seal portion 37 to the outside to seal the inner side of the inner shroud 23 from a hot combustion gas. A clearance .delta.H between a stationary portion and a rotary portion changes due to a thermal elongation. A clearance measuring sensor 14 monitors the clearance .delta.H without intermission. When the clearance .delta.H is large, the control unit 10 opens the flow regulator valve 11 to cause the air to bypass the cooler 12. When the clearance .delta.H is small, the control unit 10 closes the valve 11 to control the thermal elongation so that the clearance .delta.H may be optimized at all times. As a result, the sealing performance can be improved to avoid the contact.