Patent Publication Number: US-8123821-B2

Title: Regulating vanadium inhibitor in a gas turbine

Description:
BACKGROUND OF THE INVENTION 
     The subject matter disclosed herein relates generally to gas turbines and more specifically to regulating the injection of vanadium inhibitor in the fuel of a gas turbine. 
     BRIEF DESCRIPTION OF THE INVENTION 
     A method and system are disclosed that enable an automatic regulation of a vanadium inhibitor in a fuel of a gas turbine. In one embodiment, the method includes obtaining an indication as to whether an additional inhibitor is required in the fuel of the gas turbine based on an amount of vanadium and an inhibitor in the fuel of the gas turbine, in response to the indication that the additional inhibitor is required, having an inhibitor control system automatically instructing an injector to inject the additional inhibitor into the fuel of the gas turbine to inhibit the vanadium. 
     A first aspect of the invention provides a method comprising: obtaining an indication as to whether an additional inhibitor is required in a fuel of a gas turbine based on an amount of vanadium and an inhibitor in the fuel of the gas turbine, in response to the indication that the additional inhibitor is required, having an inhibitor control system automatically instructing an injector to inject the additional inhibitor into the fuel of the gas turbine to inhibit the vanadium. 
     A second aspect of the invention provides a system comprising: a gas turbine control system comprising an inhibitor control system including: a data analyzer that obtains an amount of vanadium and an inhibitor in a fuel of a gas turbine, a comparator for comparing the amounts of the vanadium and the inhibitor to a recommended amount for the gas turbine, a determinator for determining an amount of an additional inhibitor that is required in the fuel of the gas turbine and an injector that injects the additional inhibitor into the fuel of the gas turbine to inhibit the vanadium. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various aspects of the invention, in which: 
         FIG. 1  shows a block diagram of an illustrative environment for implementing embodiments of a system according to the invention. 
         FIG. 2  shows a flow diagram of embodiments of a method of using the system of  FIG. 1 . 
     
    
    
     It is noted that the drawings are not to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     As indicated above, aspects of the invention provide a method and system for automatically regulating a vanadium inhibitor in the fuel of a gas turbine. The methodology includes obtaining an indication as to whether an additional inhibitor is required in a fuel of a gas turbine based on an amount of vanadium and an inhibitor in the fuel of the gas turbine, and in response to the indication that the additionally inhibitor is required, having an inhibitor control system automatically instructing an injector to inject the additional inhibitor into the fuel of the gas turbine to inhibit the vanadium. 
     In one embodiment, the methodology discussed herein provides for a gas turbine control system  120  that comprises an inhibitor control system  100  that includes a data analyzer  104 , a comparator  106 , a determinator  108 , an injector  110  and an alarm  111 . Inhibitor control system  100  automates the process of monitoring the amounts of inhibitor and vanadium in the fuel of gas turbine  102  and also the injection of additional inhibitor into the fuel of gas turbine  102  if it is determined additional inhibitor is required. Inhibitor control system  100  reduces the need for operator oversight of the amounts of the vanadium and the inhibitor in the fuel of gas turbine  102  and the injection of the additional inhibitor. Additionally, inhibitor control system  100  allows for the continual injection of the additional inhibitor based on the reported amounts of the vanadium and the inhibitor contained in the fuel of gas turbine  102 . Moreover, inhibitor control system  100  reduces the possibility of operator error by automatically injecting the additional inhibitor into the fuel of gas turbine  102 . 
     Turning to the drawing,  FIG. 2  shows a flow diagram illustrating one embodiment of the process of inhibitor control system  100  is depicted. In process P 1 , data analyzer  104  obtains an amount of the vanadium and the inhibitor contained in the fuel of gas turbine  102 . Data analyzer  104  may comprise a spectrometer or any other device capable of determining the amount of vanadium and inhibitor in the fuel of gas turbine  102 . Data analyzer  104  may also archive the amounts of vanadium and inhibitor in the fuel of gas turbine  102 . In another embodiment, the output of data analyzer  104  can be reported to remote monitor  114 . Remote monitor  114  can also maintain an archive of the amounts of vanadium and inhibitor in the fuel of gas turbine  102 . In one embodiment, in process P 1 A, data analyzer  104  may report at the same site as inhibitor control system  100 . In another embodiment, in process P 1 B, data analyzer  104  may report remote monitor  114 , which may be located at any location other than where inhibitor control system  100  is located. 
     After obtaining the amounts of the vanadium and the inhibitor from data analyzer  104 , in process P 2 , comparator  106  compares the amounts of the vanadium and the inhibitor to the recommended amounts for gas turbine  102 . If the amount of the inhibitor exceeds the recommended amount (YES at process P 2 ), then data analyzer  104  repeats the obtaining an indication as to whether an additional inhibitor is required in the fuel of gas turbine  102  (process P 1 ). If the amount of the inhibitor does not exceed the recommended amount (NO at process P 2 ), then at process P 3 , determinator  108  determines the amount of additional inhibitor that may be injected into the fuel of gas turbine  102 . Determinator  108  may include a processor that performs an algorithm to determine the amount of inhibitor required or may base the amount on a lookup or any other solution. In process P 4 , injector  110  injects the additional inhibitor into the fuel of gas turbine  102 . After process P 4 , inhibitor control system  100  repeats process P 1  and obtains the amount of vanadium and inhibitor in the fuel of gas turbine  102 . 
     Returning to process P 2 , in one embodiment, comparator  106  may automatically compare the amount of the vanadium and the inhibitor in the fuel of gas turbine  102  with the recommended amounts. In an alternative embodiment, comparator  106  allows for an operator located at the site of gas turbine  102  to compare the amounts of the vanadium and the inhibitor contained in the fuel of gas turbine  102  with the recommended amounts. In another embodiment, in the event of a failure of inhibitor control system  100  or one of its components, the control of the inhibitor injection by injector  108  can be accomplished by manual control whereby an operator compares the amounts with the recommended amounts and manually adjusts the injection rate. The recommended amounts may be established by the gas turbine&#39;s manufacturer or the gas turbine&#39;s owner. 
     As noted above, if it has been determined by process P 2  that the amount of the inhibitor, as compared with the amount of vanadium in the fuel of the gas turbine, does not exceed the recommended amount, then in process P 3  determinator  108  determines the amount of additional inhibitor that injector  110 , and in process P 4 , may inject into the fuel of gas turbine  102 . In one embodiment, injector  110  automatically injects the additional inhibitor into the fuel of gas turbine  102 . In an alternative embodiment, injector  110  allows for an operator located at the site of gas turbine  102  to manually inject the additional inhibitor into the fuel of gas turbine  102 . Inhibitor may include a magnesium compound such as magnesium sulfonate, magnesium sulfate or magnesium oxide. In one embodiment, in process P 4 , injector  110  may inject the additional inhibitor into the fuel of gas turbine  102  at a ratio of approximately 3 parts inhibitor to 1 part vanadium. However, other ratios may be possible. 
     In an alternative embodiment, inhibitor control system  100  may also provide a notice from alarm  111  to an operator in the event of an incorrect amount of inhibitor to vanadium in the fuel of gas turbine  102  or if the amount of vanadium and inhibitor have not been updated in pre-determined period of time. Inhibitor control system  100  may also initiate a shutdown (gradual or immediate) of gas turbine  102  if there is an incorrect amount of inhibitor to vanadium. The magnitude of the error may be time-weighed as determined by inhibitor control system  100 . For example, a large error for a short time may initiate an immediate gas turbine  102  shutdown, while a smaller error may initiate a gradual gas turbine  102  shutdown. 
     While various embodiments are described herein, it will be appreciated from the specification that various combinations of elements, variations or improvements therein may be made by those skilled in the art, and are within the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.