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:
May. 02, 1978
Filed:
Jul. 08, 1977
John M Beatty, Prospect Park, PA (US);
Robert L Frater, Aston, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A boiler feedpump turbine (BFPT) control system for controlling the rotating speed of a boiler feedpump turbine in a selected one of at least three control modes is disclosed. The boiler feedpump turbine is mechanically coupled to a boiler feedpump for governing the flow of feedwater pumped by the feedpump to a boiler. A boiler control turbine speed signal which represents the feedwater requirement of the boiler is provided to the BPFT control system from a conventional boiler feedwater control system. The flow of feedwater pumped by the feedpump is a function of the rotating speed of the boiler feedpump turbine which is controlled in a selected one of three modes in accordance with the adjustment of a speed set point. The three control modes include adjusting the speed set point in relation to a turbine speed demand signal generated within the BFPT control system only at values below the boiler control turbine speed signal, adjusting the speed set point in relation to the boiler control turbine speed signal, and overriding the adjustment of the speed set point by the boiler control turbine speed signal to permit adjustment of the speed set point by the turbine speed demand signal beyond the value of the boiler control turbine speed signal. Transfers between the control modes are performed automatically in response to a set of predetermined conditions and commands. The BFPT additionally provides for conducting an overspeed test which permits adjustment of the speed set point by the turbine speed demand signal in a predetermined range beyond a rated turbine speed value. This overspeed test function prohibits the speed set point from remaining above the rated turbine speed values at times when not conducting the overspeed test. The BFPT control system employs a closed-loop primary speed controller which calculates its turbine speed feedback signal from a selected one of two speed transducers. The other of the two speed transducers may be used if a malfunction is detected in the selected speed transducer. The BFPT control system further incorporates a degraded manual backup controller which assumes control responsibilities when a malfunction is detected which renders the primary controller inoperative.